WIP: tests: add more tests to git crate

crates/config/src/branch_name.rs

@@ -1,5 +1,7 @@
+use derive_more::Display;
+
 /// The name of a Branch
-#[derive(Clone, Default, Debug, Hash, PartialEq, Eq, derive_more::Display)]
+#[derive(Clone, Default, Debug, Hash, PartialEq, Eq, Display, PartialOrd, Ord)]
 pub struct BranchName(String);
 impl BranchName {
     pub fn new(str: impl Into<String>) -> Self {

crates/git/Cargo.toml

@@ -55,6 +55,7 @@ actix = { workspace = true }
 # Testing
 assert2 = { workspace = true }
 rand = { workspace = true }
+pretty_assertions = { workspace = true }
 
 [lints.clippy]
 nursery = { level = "warn", priority = -1 }

crates/git/src/commit.rs

@@ -40,21 +40,19 @@ pub struct Histories {
 
 pub mod log {
 
+    use git_next_config as config;
+
     pub type Result<T> = core::result::Result<T, Error>;
 
     #[derive(Debug, thiserror::Error)]
     pub enum Error {
-        #[error("gix: {0}")]
+        #[error("branch: {branch}, error: {error}")]
-        Gix(String),
+        Gix {
+            branch: config::BranchName,
+            error: String,
+        },
 
         #[error("lock")]
         Lock,
     }
-
-    impl From<String> for Error {
-        #[cfg(not(tarpaulin_include))]
-        fn from(e: String) -> Self {
-            Self::Gix(e)
-        }
-    }
 }

crates/git/src/fetch.rs

@@ -1,3 +1,6 @@
+//
+pub type Result<T> = core::result::Result<T, Error>;
+
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("unable to open repo: {0}")]
@@ -17,4 +20,12 @@ pub enum Error {
 
     #[error("lock")]
     Lock,
+
+    #[cfg(test)]
+    #[error("expected failure in test")]
+    TestFailureExpected,
+
+    #[cfg(test)]
+    #[error("test")]
+    TestResult(#[from] Box<dyn std::error::Error>),
 }

crates/git/src/file.rs

@@ -37,7 +37,7 @@ pub enum Error {
     NoTreeInCommit(String),
 
     #[error("no .git-next.toml file found in repo")]
-    NoGitNextToml,
+    FileNotFound,
 
     #[error("find reference: {0}")]
     FindReference(String),

crates/git/src/git_ref.rs

@@ -1,6 +1,8 @@
+use derive_more::Constructor;
+
 use crate::Commit;
 
-#[derive(Clone, Debug, Hash, PartialEq, Eq, derive_more::Display)]
+#[derive(Clone, Constructor, Debug, Hash, PartialEq, Eq, derive_more::Display)]
 pub struct GitRef(String);
 impl From<Commit> for GitRef {
     fn from(value: Commit) -> Self {

crates/git/src/push.rs

@@ -40,6 +40,10 @@ pub enum Error {
 
     #[error("gix iter init: {0}")]
     GixIterInit(#[from] gix::reference::iter::init::Error),
+
+    #[cfg(test)]
+    #[error("test")]
+    TestResult(#[from] Box<dyn std::error::Error>),
 }
 
 pub fn reset(

crates/git/src/repo_details.rs

@@ -7,9 +7,7 @@ use super::{Generation, GitRemote};
 
 /// The derived information about a repo, used to interact with it
 #[derive(Clone, Default, Debug, derive_more::Display, derive_with::With)]
-#[display("gen-{}:{}:{}/{}:{}@{}/{}@{}", generation, forge.forge_type(),
+#[display("gen-{}:{}:{}/{}", generation, forge.forge_type(), forge.forge_alias(), repo_alias )]
-    forge.forge_alias(), repo_alias, forge.user(), forge.hostname(), repo_path,
-    branch)]
 pub struct RepoDetails {
     pub generation: Generation,
     pub repo_alias: RepoAlias,

crates/git/src/repository/mock.rs

@@ -6,19 +6,12 @@ use std::{
     sync::{Arc, Mutex},
 };
 
-use crate::{self as git, Repository};
+use crate as git;
-use crate::{
-    repository::{
-        open::{OpenRepository, OpenRepositoryLike},
-        Direction, RepositoryLike,
-    },
-    GitRemote, RepoDetails,
-};
 use git_next_config as config;
 
 #[derive(Debug, Default, Clone)]
 pub struct MockRepository {
-    open_repos: Arc<Mutex<HashMap<config::GitDir, MockOpenRepository>>>,
+    open_repos: Arc<Mutex<HashMap<config::GitDir, git::repository::MockOpenRepository>>>,
 }
 impl MockRepository {
     pub fn new() -> Self {
@@ -27,8 +20,11 @@ impl MockRepository {
         }
     }
 
-    pub fn given_can_be_opened(&mut self, gitdir: &config::GitDir) -> MockOpenRepository {
+    pub fn given_can_be_opened(
-        let open_repo = MockOpenRepository::new();
+        &mut self,
+        gitdir: &config::GitDir,
+    ) -> git::repository::MockOpenRepository {
+        let open_repo = git::repository::MockOpenRepository::new();
         #[allow(clippy::unwrap_used)]
         self.open_repos
             .lock()
@@ -37,19 +33,25 @@ impl MockRepository {
         open_repo
     }
 
-    pub fn seal(self) -> (Repository, Self) {
+    pub fn seal(self) -> (git::Repository, Self) {
-        (Repository::Mock(self.clone()), self)
+        (git::Repository::Mock(self.clone()), self)
     }
-    pub fn unseal(self, _repository: Repository) -> Self {
+    pub fn unseal(self, _repository: git::Repository) -> Self {
         // drop repository to allow same mutable access to mock repository
         self
     }
+    pub fn get(&self, gitdir: &config::GitDir) -> Option<git::repository::MockOpenRepository> {
+        self.open_repos
+            .lock()
+            .map(|or| or.get(gitdir).cloned())
+            .unwrap_or(None)
     }
-impl RepositoryLike for MockRepository {
+}
+impl git::repository::RepositoryLike for MockRepository {
     fn open(
         &self,
         gitdir: &config::GitDir,
-    ) -> std::result::Result<OpenRepository, crate::repository::Error> {
+    ) -> std::result::Result<git::repository::OpenRepository, crate::repository::Error> {
         #[allow(clippy::unwrap_used)]
         self.open_repos
             .lock()
@@ -62,96 +64,8 @@ impl RepositoryLike for MockRepository {
 
     fn git_clone(
         &self,
-        _repo_details: &RepoDetails,
+        _repo_details: &git::RepoDetails,
-    ) -> std::result::Result<OpenRepository, crate::repository::Error> {
+    ) -> std::result::Result<git::repository::OpenRepository, crate::repository::Error> {
         todo!("MockRepository::git_clone")
     }
 }
-
-#[derive(Clone, Debug, Default)]
-pub struct MockOpenRepository {
-    default_push_remote: Arc<Mutex<Option<GitRemote>>>,
-    default_fetch_remote: Arc<Mutex<Option<GitRemote>>>,
-}
-impl MockOpenRepository {
-    pub fn new() -> Self {
-        Self::default()
-    }
-    pub fn given_has_default_remote(&mut self, direction: Direction, remote: Option<GitRemote>) {
-        #[allow(clippy::unwrap_used)]
-        match direction {
-            Direction::Push => self
-                .default_push_remote
-                .lock()
-                .map(|mut o| match remote {
-                    Some(gr) => o.replace(gr),
-                    None => o.take(),
-                })
-                .unwrap(),
-            Direction::Fetch => self
-                .default_fetch_remote
-                .lock()
-                .map(|mut o| match remote {
-                    Some(gr) => o.replace(gr),
-                    None => o.take(),
-                })
-                .unwrap(),
-        };
-    }
-}
-impl From<MockOpenRepository> for OpenRepository {
-    fn from(value: MockOpenRepository) -> Self {
-        Self::Mock(value)
-    }
-}
-
-#[allow(clippy::unwrap_used)]
-impl OpenRepositoryLike for MockOpenRepository {
-    fn remote_branches(&self) -> git::push::Result<Vec<config::BranchName>> {
-        todo!("MockOpenRepository::remote_branched")
-    }
-    fn find_default_remote(&self, direction: Direction) -> Option<GitRemote> {
-        match direction {
-            Direction::Push => self
-                .default_push_remote
-                .lock()
-                .map(|r| r.clone())
-                .unwrap_or(None),
-            Direction::Fetch => self
-                .default_fetch_remote
-                .lock()
-                .map(|r| r.clone())
-                .unwrap_or(None),
-        }
-    }
-
-    fn fetch(&self) -> core::result::Result<(), crate::fetch::Error> {
-        todo!("MockOpenRepository::fetch")
-    }
-
-    fn push(
-        &self,
-        _repo_details: &RepoDetails,
-        _branch_name: &git_next_config::BranchName,
-        _to_commit: &crate::GitRef,
-        _force: &crate::push::Force,
-    ) -> core::result::Result<(), crate::push::Error> {
-        todo!("MockOpenRepository::push")
-    }
-
-    fn commit_log(
-        &self,
-        _branch_name: &git_next_config::BranchName,
-        _find_commits: &[git::Commit],
-    ) -> core::result::Result<Vec<crate::Commit>, git::commit::log::Error> {
-        todo!("MockOpenRepository::commit_log")
-    }
-
-    fn read_file(
-        &self,
-        _branch_name: &git_next_config::BranchName,
-        _file_name: &str,
-    ) -> git::file::Result<String> {
-        todo!("MockOpenRepository::read_file")
-    }
-}

crates/git/src/repository/mod.rs

@@ -1,7 +1,10 @@
 //
+#[cfg(test)]
 mod mock;
 mod open;
 mod real;
+#[cfg(test)]
+mod test;
 
 #[cfg(test)]
 mod tests;
@@ -9,29 +12,59 @@ mod tests;
 use git_next_config as config;
 use git_next_config::GitDir;
 
+#[cfg(test)]
 pub use mock::MockRepository;
+#[cfg(test)]
+pub use open::otest::OnFetch;
+#[cfg(test)]
+pub use open::otest::OnPush;
+#[cfg(test)]
+pub use open::MockOpenRepository;
 pub use open::OpenRepository;
+pub use open::OpenRepositoryLike;
+pub use open::RealOpenRepository;
+pub use real::RealRepository;
 use tracing::info;
 
+#[cfg(test)]
+use crate::repository::test::TestRepository;
+
 use crate::validation::repo::validate_repo;
 
 use super::RepoDetails;
 
 #[derive(Clone, Debug)]
+#[allow(clippy::large_enum_variant)]
 pub enum Repository {
     Real,
+    #[cfg(test)]
     Mock(MockRepository),
+    #[cfg(test)]
+    Test(TestRepository),
 }
+
 pub const fn new() -> Repository {
     Repository::Real
 }
+
+#[cfg(test)]
 pub fn mock() -> MockRepository {
     MockRepository::new()
-    // (Repository::Mock(mock_repository.clone()), mock_repository)
+}
+
+#[cfg(test)]
+pub const fn test(fs: kxio::fs::FileSystem) -> TestRepository {
+    TestRepository::new(false, fs, vec![], vec![])
+}
+
+#[cfg(test)]
+pub const fn test_bare(fs: kxio::fs::FileSystem) -> TestRepository {
+    TestRepository::new(true, fs, vec![], vec![])
 }
 
 /// Opens a repository, cloning if necessary
 #[tracing::instrument(skip_all)]
+#[cfg(not(tarpaulin_include))] // requires network access to either clone new and/or fetch.
 pub fn open(
     repository: &Repository,
     repo_details: &RepoDetails,
@@ -59,7 +92,10 @@ impl std::ops::Deref for Repository {
     fn deref(&self) -> &Self::Target {
         match self {
             Self::Real => &real::RealRepository,
+            #[cfg(test)]
             Self::Mock(mock_repository) => mock_repository,
+            #[cfg(test)]
+            Self::Test(test_repository) => test_repository,
         }
     }
 }

crates/git/src/repository/open/mod.rs

@@ -1,32 +1,86 @@
 //
+#![allow(dead_code)]
+
 #[cfg(test)]
 mod tests;
 
 pub mod oreal;
 
+#[cfg(test)]
+pub mod otest;
+
+#[cfg(test)]
+pub mod omock;
+
 use std::sync::{Arc, Mutex};
 
 use crate as git;
-use git::repository::open::oreal::RealOpenRepository;
 use git::repository::Direction;
 use git_next_config as config;
+#[cfg(test)]
+pub use omock::MockOpenRepository;
+pub use oreal::RealOpenRepository;
+#[cfg(test)]
+pub use otest::TestOpenRepository;
 
 #[derive(Clone, Debug)]
 pub enum OpenRepository {
+    /// A real git repository.
+    ///
+    /// This variant is the normal implementation for use in production code.
     Real(RealOpenRepository),
-    Mock(git::repository::mock::MockOpenRepository), // TODO: (#38) contain a mock model of a repo
+    /// A fake git repository.
+    ///
+    /// This variant has no on-disk presense, and only fakes some of
+    /// the behaviour of a git repository.  Once the [Self::LocalOnly]
+    /// variant is ready for use, tests should be converted to using
+    /// that instead.
+    #[cfg(test)]
+    Mock(git::repository::MockOpenRepository), // TODO: (#38) contain a mock model of a repo
+    /// A real git repository, but with preprogrammed responses to network access.
+    ///
+    /// This variant is for use only in testing. Requests to methods
+    /// that would require network access, such as to the git remote
+    /// server will result in an error, unless a predefined change
+    /// has been scheduled for that request.
+    #[cfg(test)]
+    Test(TestOpenRepository),
 }
-impl OpenRepository {
+
-    pub fn real(gix_repo: gix::Repository) -> Self {
+pub fn real(gix_repo: gix::Repository) -> OpenRepository {
-        Self::Real(oreal::RealOpenRepository::new(Arc::new(Mutex::new(
+    OpenRepository::Real(oreal::RealOpenRepository::new(Arc::new(Mutex::new(
         gix_repo,
     ))))
 }
+
 #[cfg(not(tarpaulin_include))] // don't test mocks
-    pub const fn mock(mock: git::repository::mock::MockOpenRepository) -> Self {
+#[cfg(test)]
-        Self::Mock(mock)
+pub const fn mock(mock: git::repository::MockOpenRepository) -> OpenRepository {
+    OpenRepository::Mock(mock)
 }
+
+#[cfg(not(tarpaulin_include))] // don't test mocks
+#[cfg(test)]
+pub fn test(
+    gitdir: &config::GitDir,
+    fs: kxio::fs::FileSystem,
+    on_fetch: Vec<otest::OnFetch>,
+    on_push: Vec<otest::OnPush>,
+) -> OpenRepository {
+    OpenRepository::Test(TestOpenRepository::new(gitdir, fs, on_fetch, on_push))
 }
+
+#[cfg(not(tarpaulin_include))] // don't test mocks
+#[cfg(test)]
+pub fn test_bare(
+    gitdir: &config::GitDir,
+    fs: kxio::fs::FileSystem,
+    on_fetch: Vec<otest::OnFetch>,
+    on_push: Vec<otest::OnPush>,
+) -> OpenRepository {
+    OpenRepository::Test(TestOpenRepository::new_bare(gitdir, fs, on_fetch, on_push))
+}
+
 pub trait OpenRepositoryLike {
     fn remote_branches(&self) -> git::push::Result<Vec<config::BranchName>>;
     fn find_default_remote(&self, direction: Direction) -> Option<git::GitRemote>;
@@ -61,7 +115,10 @@ impl std::ops::Deref for OpenRepository {
     fn deref(&self) -> &Self::Target {
         match self {
             Self::Real(real) => real,
+            #[cfg(test)]
             Self::Mock(mock) => mock,
+            #[cfg(test)]
+            Self::Test(test) => test,
         }
     }
 }

crates/git/src/repository/open/omock.rs

@@ -0,0 +1,118 @@
+//
+use crate as git;
+use git_next_config as config;
+
+use std::sync::{Arc, Mutex};
+
+#[derive(Clone, Debug, Default)]
+pub struct MockOpenRepository {
+    default_push_remote: Arc<Mutex<Option<git::GitRemote>>>,
+    default_fetch_remote: Arc<Mutex<Option<git::GitRemote>>>,
+    operations: Arc<Mutex<Vec<String>>>,
+}
+impl MockOpenRepository {
+    pub fn new() -> Self {
+        Self::default()
+    }
+    pub fn given_has_default_remote(
+        &mut self,
+        direction: git::repository::Direction,
+        remote: Option<git::GitRemote>,
+    ) {
+        #[allow(clippy::unwrap_used)]
+        match direction {
+            git::repository::Direction::Push => self
+                .default_push_remote
+                .lock()
+                .map(|mut o| match remote {
+                    Some(gr) => o.replace(gr),
+                    None => o.take(),
+                })
+                .unwrap(),
+            git::repository::Direction::Fetch => self
+                .default_fetch_remote
+                .lock()
+                .map(|mut o| match remote {
+                    Some(gr) => o.replace(gr),
+                    None => o.take(),
+                })
+                .unwrap(),
+        };
+    }
+
+    pub fn operations(&self) -> Vec<String> {
+        self.operations
+            .lock()
+            .map(|operations| operations.clone())
+            .unwrap_or_default()
+    }
+}
+impl From<MockOpenRepository> for git::OpenRepository {
+    fn from(value: MockOpenRepository) -> Self {
+        Self::Mock(value)
+    }
+}
+#[allow(clippy::unwrap_used)]
+impl git::repository::OpenRepositoryLike for MockOpenRepository {
+    fn remote_branches(&self) -> git::push::Result<Vec<config::BranchName>> {
+        todo!("MockOpenRepository::remote_branched")
+    }
+    fn find_default_remote(&self, direction: git::repository::Direction) -> Option<git::GitRemote> {
+        match direction {
+            git::repository::Direction::Push => self
+                .default_push_remote
+                .lock()
+                .map(|r| r.clone())
+                .unwrap_or(None),
+            git::repository::Direction::Fetch => self
+                .default_fetch_remote
+                .lock()
+                .map(|r| r.clone())
+                .unwrap_or(None),
+        }
+    }
+
+    fn fetch(&self) -> core::result::Result<(), crate::fetch::Error> {
+        self.operations
+            .lock()
+            .map_err(|_| crate::fetch::Error::Lock)
+            .map(|mut operations| operations.push("fetch".to_string()))?;
+        Ok(())
+    }
+
+    fn push(
+        &self,
+        repo_details: &git::RepoDetails,
+        branch_name: &git_next_config::BranchName,
+        to_commit: &crate::GitRef,
+        force: &crate::push::Force,
+    ) -> core::result::Result<(), crate::push::Error> {
+        let forge_alias = repo_details.forge.forge_alias();
+        let repo_alias = &repo_details.repo_alias;
+        self.operations
+            .lock()
+            .map_err(|_| crate::fetch::Error::Lock)
+            .map(|mut operations| {
+                operations.push(format!(
+                    "push fa:{forge_alias} ra:{repo_alias} bn:{branch_name} tc:{to_commit} f:{force}"
+                ))
+            })?;
+        Ok(())
+    }
+
+    fn commit_log(
+        &self,
+        _branch_name: &git_next_config::BranchName,
+        _find_commits: &[git::Commit],
+    ) -> core::result::Result<Vec<crate::Commit>, git::commit::log::Error> {
+        todo!("MockOpenRepository::commit_log")
+    }
+
+    fn read_file(
+        &self,
+        _branch_name: &git_next_config::BranchName,
+        _file_name: &str,
+    ) -> git::file::Result<String> {
+        todo!("MockOpenRepository::read_file")
+    }
+}

crates/git/src/repository/open/oreal.rs

@@ -1,13 +1,14 @@
 //
 use crate as git;
 use config::BranchName;
+use derive_more::Constructor;
 use git_next_config as config;
 
 use gix::bstr::BStr;
 use std::sync::{Arc, Mutex};
 use tracing::{info, warn};
 
-#[derive(Clone, Debug, derive_more::Constructor)]
+#[derive(Clone, Debug, Constructor)]
 pub struct RealOpenRepository(Arc<Mutex<gix::Repository>>);
 impl super::OpenRepositoryLike for RealOpenRepository {
     fn remote_branches(&self) -> git::push::Result<Vec<config::BranchName>> {
@@ -45,6 +46,7 @@ impl super::OpenRepositoryLike for RealOpenRepository {
     }
 
     #[tracing::instrument(skip_all)]
+    #[cfg(not(tarpaulin_include))] // would require writing to external service
     fn fetch(&self) -> Result<(), git::fetch::Error> {
         let Ok(repository) = self.0.lock() else {
             #[cfg(not(tarpaulin_include))] // don't test mutex lock failure
@@ -123,23 +125,40 @@ impl super::OpenRepositoryLike for RealOpenRepository {
             .lock()
             .map_err(|_| git::commit::log::Error::Lock)
             .map(|repo| {
-                let branch_name = format!("remotes/origin/{branch_name}");
+                let branch = format!("remotes/origin/{branch_name}");
-                let branch_name = BStr::new(&branch_name);
+                let branch = BStr::new(&branch);
                 let branch_head = repo
-                    .rev_parse_single(branch_name)
+                    .rev_parse_single(branch)
-                    .map_err(|e| e.to_string())?;
+                    .map_err(|e| e.to_string())
-                let object = branch_head.object().map_err(|e| e.to_string())?;
+                    .map_err(as_gix_error(branch_name.clone()))?;
-                let commit = object.try_into_commit().map_err(|e| e.to_string())?;
+                let object = branch_head
+                    .object()
+                    .map_err(|e| e.to_string())
+                    .map_err(as_gix_error(branch_name.clone()))?;
+                let commit = object
+                    .try_into_commit()
+                    .map_err(|e| e.to_string())
+                    .map_err(as_gix_error(branch_name.clone()))?;
                 let walk = repo
                     .rev_walk([commit.id])
                     .all()
-                    .map_err(|e| e.to_string())?;
+                    .map_err(|e| e.to_string())
+                    .map_err(as_gix_error(branch_name.clone()))?;
                 let mut commits = vec![];
                 for item in walk.take(limit) {
-                    let item = item.map_err(|e| e.to_string())?;
+                    let item = item
-                    let commit = item.object().map_err(|e| e.to_string())?;
+                        .map_err(|e| e.to_string())
+                        .map_err(as_gix_error(branch_name.clone()))?;
+                    let commit = item
+                        .object()
+                        .map_err(|e| e.to_string())
+                        .map_err(as_gix_error(branch_name.clone()))?;
                     let id = commit.id().to_string();
-                    let message = commit.message_raw().map_err(|e| e.to_string())?.to_string();
+                    let message = commit
+                        .message_raw()
+                        .map_err(|e| e.to_string())
+                        .map_err(as_gix_error(branch_name.clone()))?
+                        .to_string();
                     let commit = git::Commit::new(
                         git::commit::Sha::new(id),
                         git::commit::Message::new(message),
@@ -171,8 +190,8 @@ impl super::OpenRepositoryLike for RealOpenRepository {
                 let commit = obj.into_commit();
                 let tree = commit.tree()?;
                 let ent = tree
-                    .find_entry(".git-next.toml")
+                    .find_entry(file_name)
-                    .ok_or(git::file::Error::NoGitNextToml)?;
+                    .ok_or(git::file::Error::FileNotFound)?;
                 let fobj = ent.object()?;
                 let blob = fobj.into_blob().take_data();
                 let content = String::from_utf8(blob)?;
@@ -181,6 +200,10 @@ impl super::OpenRepositoryLike for RealOpenRepository {
     }
 }
 
+fn as_gix_error(branch: BranchName) -> impl FnOnce(String) -> git::commit::log::Error {
+    |error| git::commit::log::Error::Gix { branch, error }
+}
+
 impl From<&gix::Url> for git::GitRemote {
     fn from(url: &gix::Url) -> Self {
         let host = url.host().unwrap_or_default();

crates/git/src/repository/open/otest.rs

@@ -0,0 +1,183 @@
+//
+use crate as git;
+use derive_more::Constructor;
+use git_next_config as config;
+
+use std::{
+    cell::Cell,
+    sync::{Arc, Mutex},
+};
+
+use assert2::let_assert;
+
+pub type OnFetchFn =
+    fn(&config::RepoBranches, &config::GitDir, &kxio::fs::FileSystem) -> git::fetch::Result<()>;
+#[derive(Clone, Debug, Constructor)]
+pub struct OnFetch {
+    repo_branches: config::RepoBranches,
+    gitdir: config::GitDir,
+    fs: kxio::fs::FileSystem,
+    action: OnFetchFn,
+}
+impl OnFetch {
+    pub fn invoke(&self) -> git::fetch::Result<()> {
+        (self.action)(&self.repo_branches, &self.gitdir, &self.fs)
+    }
+}
+
+pub type OnPushFn = fn(
+    &git::RepoDetails,
+    &config::BranchName,
+    &git::GitRef,
+    &git::push::Force,
+    &config::RepoBranches,
+    &config::GitDir,
+    &kxio::fs::FileSystem,
+) -> git::push::Result<()>;
+#[derive(Clone, Debug, Constructor)]
+pub struct OnPush {
+    repo_branches: config::RepoBranches,
+    gitdir: config::GitDir,
+    fs: kxio::fs::FileSystem,
+    action: OnPushFn,
+}
+impl OnPush {
+    pub fn invoke(
+        &self,
+        repo_details: &git::RepoDetails,
+        branch_name: &config::BranchName,
+        to_commit: &git::GitRef,
+        force: &git::push::Force,
+    ) -> git::push::Result<()> {
+        (self.action)(
+            repo_details,
+            branch_name,
+            to_commit,
+            force,
+            &self.repo_branches,
+            &self.gitdir,
+            &self.fs,
+        )
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct TestOpenRepository {
+    gitdir: config::GitDir,
+    fs: kxio::fs::FileSystem,
+    on_fetch: Vec<OnFetch>,
+    fetch_counter: Cell<usize>,
+    on_push: Vec<OnPush>,
+    push_counter: Cell<usize>,
+    real: git::repository::RealOpenRepository,
+}
+impl git::repository::OpenRepositoryLike for TestOpenRepository {
+    fn remote_branches(&self) -> git::push::Result<Vec<config::BranchName>> {
+        self.real.remote_branches()
+    }
+
+    fn find_default_remote(&self, direction: git::repository::Direction) -> Option<git::GitRemote> {
+        self.real.find_default_remote(direction)
+    }
+
+    fn fetch(&self) -> Result<(), git::fetch::Error> {
+        let i = self.fetch_counter.get();
+        eprintln!("Fetch: {i}");
+        self.fetch_counter.set(i + 1);
+        self.on_fetch.get(i).map(|f| f.invoke()).unwrap_or_else(|| {
+            unimplemented!("Unexpected fetch");
+        })
+    }
+
+    fn push(
+        &self,
+        repo_details: &git::RepoDetails,
+        branch_name: &config::BranchName,
+        to_commit: &git::GitRef,
+        force: &git::push::Force,
+    ) -> git::push::Result<()> {
+        let i = self.push_counter.get();
+        self.push_counter.set(i + 1);
+        self.on_push
+            .get(i)
+            .map(|f| f.invoke(repo_details, branch_name, to_commit, force))
+            .unwrap_or_else(|| {
+                unimplemented!("Unexpected push");
+            })
+    }
+
+    fn commit_log(
+        &self,
+        branch_name: &config::BranchName,
+        find_commits: &[git::Commit],
+    ) -> git::commit::log::Result<Vec<crate::Commit>> {
+        self.real.commit_log(branch_name, find_commits)
+    }
+
+    fn read_file(
+        &self,
+        branch_name: &config::BranchName,
+        file_name: &str,
+    ) -> git::file::Result<String> {
+        self.real.read_file(branch_name, file_name)
+    }
+}
+impl TestOpenRepository {
+    pub fn new(
+        gitdir: &config::GitDir,
+        fs: kxio::fs::FileSystem,
+        on_fetch: Vec<OnFetch>,
+        on_push: Vec<OnPush>,
+    ) -> Self {
+        let pathbuf = fs.base().join(gitdir.to_path_buf());
+        let_assert!(Ok(gix) = gix::init(pathbuf), "git init bare");
+        Self::write_origin(gitdir, &fs);
+        Self {
+            gitdir: gitdir.clone(),
+            fs,
+            on_fetch,
+            fetch_counter: Cell::new(0),
+            on_push,
+            push_counter: Cell::new(0),
+            real: git::repository::RealOpenRepository::new(Arc::new(Mutex::new(gix))),
+        }
+    }
+    pub fn new_bare(
+        gitdir: &config::GitDir,
+        fs: kxio::fs::FileSystem,
+        on_fetch: Vec<OnFetch>,
+        on_push: Vec<OnPush>,
+    ) -> Self {
+        let pathbuf = fs.base().join(gitdir.to_path_buf());
+        let_assert!(Ok(gix) = gix::init_bare(pathbuf), "git init bare");
+        Self::write_origin(gitdir, &fs);
+        Self {
+            gitdir: gitdir.clone(),
+            fs,
+            on_fetch,
+            fetch_counter: Cell::new(0),
+            on_push,
+            push_counter: Cell::new(0),
+            real: git::repository::RealOpenRepository::new(Arc::new(Mutex::new(gix))),
+        }
+    }
+
+    fn write_origin(gitdir: &config::GitDir, fs: &kxio::fs::FileSystem) {
+        let config_file = fs.base().join(gitdir.to_path_buf()).join(".git/config");
+        #[allow(clippy::expect_used)]
+        let contents = fs
+            .file_read_to_string(&config_file)
+            .expect("read original .git/config");
+        let updated_contents = format!(
+            r#"{contents}
+[remote "origin"]
+    url = git@foo.example,net
+    fetch = +refs/heads/*:refs/remotes/origin/*
+        "#
+        );
+        eprintln!("{config_file:?}:\n{updated_contents}");
+        #[allow(clippy::expect_used)]
+        fs.file_write(&config_file, &updated_contents)
+            .expect("write updated .git/config");
+    }
+}

crates/git/src/repository/open/tests.rs

@@ -1,22 +1,27 @@
 //
+use crate as git;
+use crate::repository::RepositoryLike as _;
+use git_next_config as config;
+
+use assert2::let_assert;
 
 mod find_default_remote {
-    use assert2::let_assert;
+    use super::*;
-    use git_next_config::{GitDir, Hostname, RepoPath};
+
+    use assert2::let_assert;
 
-    use crate::GitRemote;
     #[test]
     fn should_find_default_push_remote() {
         // uses the current repo
         let_assert!(Ok(cwd) = std::env::current_dir());
-        let gitdir = GitDir::from(cwd.join("../..")); // from ./crate/git directory to the project rook
+        let gitdir = config::GitDir::from(cwd.join("../..")); // from ./crate/git directory to the project rook
         let_assert!(Ok(repo) = crate::repository::new().open(&gitdir));
         let_assert!(Some(remote) = repo.find_default_remote(crate::repository::Direction::Push));
         assert_eq!(
             remote,
-            GitRemote::new(
+            git::GitRemote::new(
-                Hostname::new("git.kemitix.net"),
+                config::Hostname::new("git.kemitix.net"),
-                RepoPath::new("kemitix/git-next".to_string())
+                config::RepoPath::new("kemitix/git-next".to_string())
             )
         )
     }
@@ -36,3 +41,94 @@ mod fetch {
         let_assert!(Ok(_) = repo.fetch());
     }
 }
+
+mod remote_branches {
+    use super::*;
+    #[test]
+    // assumes running in the git-next repo which should have main, next and dev as remote branches
+    fn should_return_remote_branches() {
+        let open_repo = given_open_real_repository();
+        let_assert!(Ok(remote_branches) = open_repo.remote_branches());
+        assert!(remote_branches.contains(&config::BranchName::new("main")));
+        assert!(remote_branches.contains(&config::BranchName::new("next")));
+        assert!(remote_branches.contains(&config::BranchName::new("dev")));
+    }
+}
+mod commit_log {
+    use git::tests::given;
+
+    use super::*;
+
+    #[test]
+    // assumes running in the git-next repo which should have main, next and dev as remote branches
+    fn should_return_single_item_in_commit_log_when_not_searching() {
+        let open_repo = given_open_real_repository();
+        let_assert!(Ok(result) = open_repo.commit_log(&config::BranchName::new("dev"), &[]));
+        assert_eq!(result.len(), 1)
+    }
+
+    #[test]
+    // assumes running in the git-next repo which should have main, next and dev as remote branches
+    fn should_return_capacity_50_in_commit_log_when_searching_for_garbage() {
+        let open_repo = given_open_real_repository();
+        let_assert!(
+            Ok(result) =
+                open_repo.commit_log(&config::BranchName::new("dev"), &[given::a_commit()])
+        );
+        assert_eq!(result.len(), 50)
+    }
+
+    #[test]
+    // assumes running in the git-next repo which should have main, next and dev as remote branches
+    fn should_return_25_in_commit_log_when_searching_for_25th_item() {
+        let open_repo = given_open_real_repository();
+        // search to garbage to get full page of 50 items
+        let_assert!(
+            Ok(long_list) =
+                open_repo.commit_log(&config::BranchName::new("dev"), &[given::a_commit()])
+        );
+        // pick the 25th item
+        let search = &long_list[24]; // zero-based
+                                     // search for the 25th item
+        let_assert!(
+            Ok(result) = open_repo.commit_log(&config::BranchName::new("dev"), &[search.clone()])
+        );
+        // returns
+        assert_eq!(result.len(), 25)
+    }
+}
+mod read_file {
+    use git::tests::given;
+
+    use super::*;
+
+    #[test]
+    // assumes running in the git-next repo which should have main, next and dev as remote branches
+    fn should_return_file() {
+        let open_repo = given_open_real_repository();
+        let_assert!(
+            Ok(result) =
+                open_repo.read_file(&config::BranchName::new("dev"), "server-default.toml")
+        );
+        let expected = include_str!("../../../../../server-default.toml");
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    // assumes running in the git-next repo which should have main, next and dev as remote branches
+    fn should_error_on_missing_file() {
+        let open_repo = given_open_real_repository();
+        let_assert!(
+            Err(err) = open_repo.read_file(&config::BranchName::new("dev"), &given::a_name())
+        );
+        assert!(matches!(err, git::file::Error::FileNotFound));
+    }
+}
+
+fn given_open_real_repository() -> git::OpenRepository {
+    // assumes the current directory is a clone of this repo
+    let_assert!(Ok(current_dir) = std::env::current_dir()); // ./crates/git
+    let gitdir: config::GitDir = current_dir.join("../..").into(); // cd back to project root
+    let_assert!(Ok(real_open_repository) = git::repository::RealRepository.open(&gitdir));
+    real_open_repository
+}

crates/git/src/repository/real.rs

@@ -1,22 +1,23 @@
+//
 use std::sync::atomic::AtomicBool;
 
+use crate as git;
 use derive_more::Deref as _;
 use git_next_config::GitDir;
 
-use crate::{
-    repository::{open::OpenRepository, Error, RepositoryLike},
-    RepoDetails,
-};
-
 pub struct RealRepository;
-impl RepositoryLike for RealRepository {
+impl git::repository::RepositoryLike for RealRepository {
-    fn open(&self, gitdir: &GitDir) -> Result<OpenRepository, Error> {
+    fn open(&self, gitdir: &GitDir) -> Result<git::OpenRepository, git::repository::Error> {
         let gix_repo = gix::ThreadSafeRepository::open(gitdir.to_path_buf())?.to_thread_local();
-        Ok(OpenRepository::real(gix_repo))
+        Ok(git::repository::open::real(gix_repo))
     }
 
     #[tracing::instrument(skip_all)]
-    fn git_clone(&self, repo_details: &RepoDetails) -> Result<OpenRepository, Error> {
+    #[cfg(not(tarpaulin_include))] // requires external server
+    fn git_clone(
+        &self,
+        repo_details: &git::RepoDetails,
+    ) -> Result<git::OpenRepository, git::repository::Error> {
         tracing::info!("creating");
         use secrecy::ExposeSecret;
         let (gix_repo, _outcome) = gix::prepare_clone_bare(
@@ -26,6 +27,6 @@ impl RepositoryLike for RealRepository {
         .fetch_only(gix::progress::Discard, &AtomicBool::new(false))?;
         tracing::info!("created");
 
-        Ok(OpenRepository::real(gix_repo))
+        Ok(git::repository::open::real(gix_repo))
     }
 }

crates/git/src/repository/test.rs

@@ -0,0 +1,53 @@
+//
+use derive_more::Constructor;
+
+use crate as git;
+use git::repository::RepositoryLike;
+use git_next_config as config;
+
+#[derive(Clone, Debug, Constructor)]
+pub struct TestRepository {
+    is_bare: bool,
+    fs: kxio::fs::FileSystem,
+    on_fetch: Vec<git::repository::open::otest::OnFetch>,
+    on_push: Vec<git::repository::open::otest::OnPush>,
+}
+impl TestRepository {
+    pub fn on_fetch(&mut self, on_fetch: git::repository::OnFetch) {
+        self.on_fetch.push(on_fetch);
+    }
+
+    pub fn on_push(&mut self, on_push: git::repository::OnPush) {
+        self.on_push.push(on_push);
+    }
+
+    pub const fn fs(&self) -> &kxio::fs::FileSystem {
+        &self.fs
+    }
+}
+impl RepositoryLike for TestRepository {
+    fn open(&self, gitdir: &config::GitDir) -> super::Result<crate::OpenRepository> {
+        if self.is_bare {
+            Ok(git::repository::open::test_bare(
+                gitdir,
+                self.fs.clone(),
+                self.on_fetch.clone(),
+                self.on_push.clone(),
+            ))
+        } else {
+            Ok(git::repository::open::test(
+                gitdir,
+                self.fs.clone(),
+                self.on_fetch.clone(),
+                self.on_push.clone(),
+            ))
+        }
+    }
+
+    fn git_clone(
+        &self,
+        _repo_details: &crate::RepoDetails,
+    ) -> super::Result<crate::OpenRepository> {
+        todo!()
+    }
+}

crates/git/src/tests.rs

@@ -81,23 +81,59 @@ mod gitremote {
     }
 }
 mod push {
-    use crate::{commit, push::Force, Commit, GitRef};
+    use super::*;
+    use crate::GitRef;
 
     #[test]
     fn force_no_should_display() {
-        assert_eq!(Force::No.to_string(), "fast-forward")
+        assert_eq!(git::push::Force::No.to_string(), "fast-forward")
     }
+
     #[test]
     fn force_from_should_display() {
-        let commit = Commit::new(
+        let sha = given::a_name();
-            commit::Sha::new("sha".to_string()),
+        let commit = given::a_commit_with_sha(&git::commit::Sha::new(sha.clone()));
-            commit::Message::new("message".to_string()),
-        );
         assert_eq!(
-            Force::From(GitRef::from(commit)).to_string(),
+            git::push::Force::From(GitRef::from(commit)).to_string(),
-            "force-if-from:sha"
+            format!("force-if-from:{sha}")
         )
     }
+
+    mod reset {
+        use super::*;
+        use crate::{tests::given, OpenRepository};
+        use assert2::let_assert;
+
+        #[test]
+        fn should_perform_a_fetch_then_push() {
+            let fs = given::a_filesystem();
+            let (mock_open_repository, gitdir, mock_repository) = given::an_open_repository(&fs);
+            let open_repository: OpenRepository = mock_open_repository.into();
+            let repo_details = given::repo_details(&fs);
+            let branch_name = &repo_details.branch;
+            let commit = given::a_commit();
+            let gitref = GitRef::from(commit);
+            let_assert!(
+                Ok(_) = git::push::reset(
+                    &open_repository,
+                    &repo_details,
+                    branch_name,
+                    &gitref,
+                    &git::push::Force::No
+                )
+            );
+            let_assert!(Some(mock_open_repository) = mock_repository.get(&gitdir));
+            let operations = mock_open_repository.operations();
+            let forge_alias = repo_details.forge.forge_alias();
+            let repo_alias = &repo_details.repo_alias;
+            let to_commit = gitref;
+            let force = "fast-forward";
+            assert_eq!(
+                operations,
+                vec![format!("fetch"), format!("push fa:{forge_alias} ra:{repo_alias} bn:{branch_name} tc:{to_commit} f:{force}")]
+            );
+        }
+    }
 }
 mod repo_details {
 
@@ -172,13 +208,17 @@ mod repo_details {
         );
     }
 }
-mod given {
+pub mod given {
     #![allow(dead_code)]
     //
-    use crate as git;
+    use crate::{
+        self as git,
+        repository::{MockOpenRepository, MockRepository},
+        tests::given,
+    };
     use config::{
         BranchName, ForgeAlias, ForgeConfig, ForgeType, GitDir, RepoAlias, RepoBranches,
-        ServerRepoConfig, WebhookAuth, WebhookId,
+        RepoConfig, ServerRepoConfig, WebhookAuth, WebhookId,
     };
     use git_next_config as config;
 
@@ -201,7 +241,11 @@ mod given {
     }
 
     pub fn repo_branches() -> RepoBranches {
-        RepoBranches::new(a_name(), a_name(), a_name())
+        RepoBranches::new(
+            format!("main-{}", a_name()),
+            format!("next-{}", a_name()),
+            format!("dev-{}", a_name()),
+        )
     }
 
     pub fn a_forge_alias() -> ForgeAlias {
@@ -282,6 +326,10 @@ mod given {
         )
     }
 
+    pub fn a_repo_config() -> RepoConfig {
+        RepoConfig::new(given::repo_branches(), config::RepoConfigSource::Repo)
+    }
+
     pub fn a_commit() -> git::Commit {
         git::Commit::new(a_commit_sha(), a_commit_message())
     }
@@ -335,11 +383,12 @@ mod given {
         )
     }
 
-    // pub fn an_open_repository(fs: &kxio::fs::FileSystem) -> (OpenRepository, MockRepository) {
+    pub fn an_open_repository(
-    //     let (repo, mock) = git::repository::mock();
+        fs: &kxio::fs::FileSystem,
-    //
+    ) -> (MockOpenRepository, GitDir, MockRepository) {
-    //     let gitdir = a_git_dir(fs);
+        let mut mock = git::repository::mock();
-    //     let op = repo.open(&gitdir).unwrap();
+        let gitdir = a_git_dir(fs);
-    //     (op, mock)
+        let or = mock.given_can_be_opened(&gitdir);
-    // }
+        (or, gitdir, mock)
+    }
 }

crates/git/src/validation/mod.rs

@@ -1,2 +1,5 @@
 pub mod positions;
 pub mod repo;
+
+#[cfg(test)]
+mod tests;

crates/git/src/validation/tests.rs

@@ -0,0 +1,448 @@
+//
+use crate as git;
+
+use git::tests::given;
+use git_next_config as config;
+
+use assert2::let_assert;
+
+pub type TestResult = core::result::Result<(), Box<dyn std::error::Error>>;
+
+mod positions {
+    use super::*;
+
+    use git::repository::RepositoryLike as _;
+
+    mod validate_positions {
+
+        use git::validation::positions::validate_positions;
+
+        use super::*;
+
+        #[test]
+        fn where_fetch_fails_should_error() {
+            let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
+            let gitdir: config::GitDir = fs.base().to_path_buf().into();
+            let mut test_repository = git::repository::test(fs.clone());
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                given::repo_branches(),
+                gitdir.clone(),
+                fs.clone(),
+                |_, _, _| git::fetch::Result::Err(git::fetch::Error::TestFailureExpected),
+            ));
+            let_assert!(Ok(repository) = test_repository.open(&gitdir), "open repo");
+            let repo_details = given::repo_details(&fs).with_gitdir(gitdir);
+            let repo_config = given::a_repo_config();
+
+            let_assert!(
+                Err(err) = validate_positions(&repository, &repo_details, repo_config),
+                "validate"
+            );
+
+            assert!(matches!(
+                err,
+                git::validation::positions::Error::Fetch(git::fetch::Error::TestFailureExpected)
+            ));
+        }
+
+        #[test]
+        fn where_main_branch_is_missing_or_commit_log_is_empty_should_error() {
+            let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
+            let gitdir: config::GitDir = fs.base().to_path_buf().into();
+            let mut test_repository = git::repository::test(fs.clone());
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                given::repo_branches(),
+                gitdir.clone(),
+                fs.clone(),
+                |_, _, _| git::fetch::Result::Ok(()),
+            ));
+            // test repo is a new bare repo with no commits
+            let_assert!(Ok(repository) = test_repository.open(&gitdir), "open repo");
+            let repo_details = given::repo_details(&fs).with_gitdir(gitdir);
+            let repo_config = given::a_repo_config();
+
+            let_assert!(
+                Err(err) = validate_positions(&repository, &repo_details, repo_config.clone()),
+                "validate"
+            );
+            let branch_name = repo_config.branches().main();
+            let error_message = format!(
+                r#"The ref partially named "remotes/origin/{branch_name}" could not be found"#
+            );
+            assert!(matches!(
+                err,
+                git::validation::positions::Error::CommitLog(git::commit::log::Error::Gix {
+                    branch,
+                    error
+                }) if branch == branch_name && error == error_message
+            ));
+        }
+
+        #[test]
+        fn where_next_branch_is_missing_or_commit_log_is_empty_should_error() {
+            //given
+            let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
+            let gitdir: config::GitDir = fs.base().to_path_buf().into();
+            let mut test_repository = git::repository::test(fs.clone());
+            let repo_config = given::a_repo_config();
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                repo_config.branches().clone(),
+                gitdir.clone(),
+                fs.clone(),
+                |branches, gitdir, fs| {
+                    // add a commit to main
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
+                    then::push_branch(fs, gitdir, &branches.main())?;
+                    git::fetch::Result::Ok(())
+                },
+            ));
+            let_assert!(Ok(repository) = test_repository.open(&gitdir), "open repo");
+            let repo_details = given::repo_details(&fs).with_gitdir(gitdir);
+
+            //when
+            let_assert!(
+                Err(err) = validate_positions(&repository, &repo_details, repo_config.clone()),
+                "validate"
+            );
+
+            //then
+            let branch_name = repo_config.branches().next();
+            let error_message = format!(
+                r#"The ref partially named "remotes/origin/{branch_name}" could not be found"#
+            );
+            assert!(matches!(
+                err,
+                git::validation::positions::Error::CommitLog(git::commit::log::Error::Gix {
+                    branch,
+                    error
+                }) if branch == branch_name && error == error_message
+            ));
+        }
+
+        #[test]
+        fn where_dev_branch_is_missing_or_commit_log_is_empty_should_error() {
+            //given
+            let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
+            let gitdir: config::GitDir = fs.base().to_path_buf().into();
+            let mut test_repository = git::repository::test(fs.clone());
+            let repo_config = given::a_repo_config();
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                repo_config.branches().clone(),
+                gitdir.clone(),
+                fs.clone(),
+                |branches, gitdir, fs| {
+                    // add a commit to main
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
+                    then::push_branch(fs, gitdir, &branches.main())?;
+                    // add a commit to next
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.next())?;
+                    then::push_branch(fs, gitdir, &branches.next())?;
+                    git::fetch::Result::Ok(())
+                },
+            ));
+            let_assert!(Ok(repository) = test_repository.open(&gitdir), "open repo");
+            let repo_details = given::repo_details(&fs).with_gitdir(gitdir);
+
+            //when
+            let_assert!(
+                Err(err) = validate_positions(&repository, &repo_details, repo_config.clone()),
+                "validate"
+            );
+
+            //then
+            let branch_name = repo_config.branches().dev();
+            let error_message = format!(
+                r#"The ref partially named "remotes/origin/{branch_name}" could not be found"#
+            );
+            assert!(matches!(
+                err,
+                git::validation::positions::Error::CommitLog(git::commit::log::Error::Gix {
+                    branch,
+                    error
+                }) if branch == branch_name && error == error_message
+            ));
+        }
+
+        #[test]
+        fn where_dev_branch_is_not_based_on_main_should_error() {
+            //given
+            let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
+            let gitdir: config::GitDir = fs.base().to_path_buf().into();
+            let mut test_repository = git::repository::test(fs.clone());
+            let repo_config = given::a_repo_config();
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                repo_config.branches().clone(),
+                gitdir.clone(),
+                fs.clone(),
+                |branches, gitdir, fs| {
+                    //             /--- 4 next
+                    // 0 --- 1 --- 3 main
+                    //        \--- 2 dev
+                    // add a commit to main (0 -> 1)
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
+                    then::push_branch(fs, gitdir, &branches.main())?;
+                    // add a commit to dev ( 1 -> 2)
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.dev())?;
+                    then::push_branch(fs, gitdir, &branches.dev())?;
+                    // switch back to main
+                    then::git_switch(&branches.main(), gitdir)?;
+                    // add a second commit to main (1 -> 3)
+                    then::git_log_all(gitdir)?;
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
+                    then::push_branch(fs, gitdir, &branches.main())?;
+                    // add a commit to next 1 -> 4
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.next())?;
+                    then::push_branch(fs, gitdir, &branches.next())?;
+                    then::git_log_all(gitdir)?;
+                    git::fetch::Result::Ok(())
+                },
+            ));
+            let_assert!(Ok(repository) = test_repository.open(&gitdir), "open repo");
+            let repo_details = given::repo_details(&fs).with_gitdir(gitdir);
+
+            //when
+            let_assert!(
+                Err(err) = validate_positions(&repository, &repo_details, repo_config.clone()),
+                "validate"
+            );
+
+            //then
+            assert!(matches!(
+                err,
+                git::validation::positions::Error::DevBranchNotBasedOn { dev, other }
+                if dev == repo_config.branches().dev() && other == repo_config.branches().main()
+            ));
+        }
+
+        #[test]
+        fn where_next_branch_is_not_based_on_main_should_reset_next_branch_to_main_and_then_error()
+        {
+            //given
+            let_assert!(Ok(fs) = kxio::fs::temp(), "temp fs");
+            let gitdir: config::GitDir = fs.base().to_path_buf().into();
+            let mut test_repository = git::repository::test(fs.clone());
+            let repo_config = given::a_repo_config();
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                repo_config.branches().clone(),
+                gitdir.clone(),
+                fs.clone(),
+                |branches, gitdir, fs| {
+                    //             /--- 4 dev
+                    // 0 --- 1 --- 3 main
+                    //        \--- 2 next
+                    // add a commit to main (0 -> 1)
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
+                    then::push_branch(fs, gitdir, &branches.main())?;
+                    // add a commit to next (1 -> 2)
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.next())?;
+                    then::push_branch(fs, gitdir, &branches.next())?;
+                    // switch back to main (1)
+                    then::git_switch(&branches.main(), gitdir)?;
+                    // add a second commit to main (1 -> 3)
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.main())?;
+                    then::push_branch(fs, gitdir, &branches.main())?;
+                    // add a commit to dev (3 -> 4)
+                    then::create_a_commit_on_branch(fs, gitdir, &branches.dev())?;
+                    then::push_branch(fs, gitdir, &branches.dev())?;
+
+                    then::git_log_all(gitdir)?;
+                    git::fetch::Result::Ok(())
+                },
+            ));
+            // second fetch as prep to push
+            test_repository.on_fetch(git::repository::OnFetch::new(
+                repo_config.branches().clone(),
+                gitdir.clone(),
+                fs.clone(),
+                |_branches, _gitdir, _fs| {
+                    // don't change anything
+                    git::fetch::Result::Ok(())
+                },
+            ));
+            test_repository.on_push(git::repository::OnPush::new(
+                repo_config.branches().clone(),
+                gitdir.clone(),
+                fs.clone(),
+                |_repo_details, branch_name, gitref, _force, repo_branches, gitdir, fs| {
+                    assert_eq!(
+                        branch_name,
+                        &repo_branches.next(),
+                        "branch to reset should be 'next'"
+                    );
+                    let sha_main = then::get_sha_for_branch(fs, gitdir, &repo_branches.main())?;
+                    assert_eq!(
+                        gitref, &sha_main,
+                        "should reset to the sha of the 'main' branch"
+                    );
+                    git::push::Result::Ok(())
+                },
+            ));
+            let_assert!(Ok(repository) = test_repository.open(&gitdir), "open repo");
+            let repo_details = given::repo_details(&fs).with_gitdir(gitdir);
+
+            //when
+            let_assert!(
+                Err(err) = validate_positions(&repository, &repo_details, repo_config.clone()),
+                "validate"
+            );
+
+            //then
+            eprintln!("{err:?}");
+            // NOTE: assertions for correct push are in on_push above
+            assert!(matches!(
+                err,
+                git::validation::positions::Error::NextBranchResetRequired(branch)
+                if branch == repo_config.branches().next()
+            ));
+        }
+        // where next branch os not based on main and reset of next fails should error
+        // where dev branch is not based on next should reset next branch to main and then error
+        // where dev branch is not based on next and reset of next fails should error
+        // where dev branch is not based on main should error
+    }
+}
+mod then {
+    use std::path::{Path, PathBuf};
+
+    use super::*;
+
+    pub fn create_a_commit_on_branch(
+        fs: &kxio::fs::FileSystem,
+        gitdir: &config::GitDir,
+        branch_name: &config::BranchName,
+    ) -> TestResult {
+        // git checkout ${branch_name}
+        git_checkout(branch_name, gitdir)?;
+        // echo ${word} > file-${word}
+        let word = given::a_name();
+        let pathbuf = PathBuf::from(gitdir);
+        let file = fs.base().join(pathbuf).join(&word);
+        #[allow(clippy::expect_used)]
+        fs.file_write(&file, &word)?;
+        // git add ${file}
+        git_add_file(gitdir, &file)?;
+        // git commit -m"Added ${file}"
+        git_commit(gitdir, &file)?;
+
+        Ok(())
+    }
+
+    pub fn push_branch(
+        fs: &kxio::fs::FileSystem,
+        gitdir: &config::GitDir,
+        branch_name: &config::BranchName,
+    ) -> TestResult {
+        let gitrefs = fs
+            .base()
+            .join(gitdir.to_path_buf())
+            .join(".git")
+            .join("refs");
+        let local_branch = gitrefs.join("heads").join(branch_name.to_string().as_str());
+        let origin_heads = gitrefs.join("remotes").join("origin");
+        let remote_branch = origin_heads.join(branch_name.to_string().as_str());
+        let contents = fs.file_read_to_string(&local_branch)?;
+        fs.dir_create_all(&origin_heads)?;
+        fs.file_write(&remote_branch, &contents)?;
+        Ok(())
+    }
+
+    pub fn git_checkout(
+        branch_name: &git_next_config::BranchName,
+        gitdir: &git_next_config::GitDir,
+    ) -> TestResult {
+        exec(
+            format!("git checkout -b {}", branch_name),
+            std::process::Command::new("git")
+                .current_dir(gitdir.to_path_buf())
+                .args(["checkout", "-b", branch_name.to_string().as_str()])
+                .output()?,
+        )
+    }
+
+    pub fn git_switch(
+        branch_name: &git_next_config::BranchName,
+        gitdir: &git_next_config::GitDir,
+    ) -> TestResult {
+        exec(
+            format!("git switch {}", branch_name),
+            std::process::Command::new("git")
+                .current_dir(gitdir.to_path_buf())
+                .args(["switch", branch_name.to_string().as_str()])
+                .output()?,
+        )
+    }
+
+    fn exec(label: String, output: std::process::Output) -> TestResult {
+        eprintln!("== {label}");
+        eprintln!(
+            "\nstdout:\n{}",
+            String::from_utf8_lossy(output.stdout.as_slice())
+        );
+        eprintln!(
+            "\nstderr:\n{}",
+            String::from_utf8_lossy(output.stderr.as_slice())
+        );
+        eprintln!("=============================");
+        Ok(())
+    }
+
+    fn git_add_file(gitdir: &git_next_config::GitDir, file: &Path) -> TestResult {
+        exec(
+            format!("git add {file:?}"),
+            std::process::Command::new("git")
+                .current_dir(gitdir.to_path_buf())
+                .args(["add", file.display().to_string().as_str()])
+                .output()?,
+        )
+    }
+
+    fn git_commit(gitdir: &git_next_config::GitDir, file: &Path) -> TestResult {
+        exec(
+            format!(r#"git commit -m"Added {file:?}""#),
+            std::process::Command::new("git")
+                .current_dir(gitdir.to_path_buf())
+                .args([
+                    "commit",
+                    format!(r#"-m"Added {}"#, file.display().to_string().as_str()).as_str(),
+                ])
+                .output()?,
+        )
+    }
+
+    pub fn git_log_all(gitdir: &config::GitDir) -> TestResult {
+        exec(
+            "git log --all --oneline --decorate --graph".to_string(),
+            std::process::Command::new("git")
+                .current_dir(gitdir.to_path_buf())
+                .args(["log", "--all", "--oneline", "--decorate", "--graph"])
+                .output()?,
+        )
+    }
+
+    #[allow(dead_code)]
+    fn ls_l(gitdir: &git_next_config::GitDir) -> TestResult {
+        exec(
+            "ls -l".to_string(),
+            std::process::Command::new("ls")
+                .current_dir(gitdir.to_path_buf())
+                .args(["-la"])
+                .output()?,
+        )
+    }
+
+    pub fn get_sha_for_branch(
+        fs: &kxio::fs::FileSystem,
+        gitdir: &git_next_config::GitDir,
+        branch_name: &git_next_config::BranchName,
+    ) -> Result<git::GitRef, Box<dyn std::error::Error>> {
+        let main_ref = fs
+            .base()
+            .join(gitdir.to_path_buf())
+            .join(".git")
+            .join("refs")
+            .join("heads")
+            .join(branch_name.to_string().as_str());
+        let sha = fs.file_read_to_string(&main_ref)?;
+        Ok(git::GitRef::new(sha.trim().to_string()))
+    }
+}

crates/repo-actor/src/lib.rs

@@ -93,7 +93,7 @@ impl Actor for RepoActor {
 pub struct CloneRepo;
 impl Handler<CloneRepo> for RepoActor {
     type Result = ();
-    #[tracing::instrument(name = "RepoActor::CloneRepo", skip_all, fields(repo = %self.repo_details, gitdir = %self.repo_details.gitdir))]
+    #[tracing::instrument(name = "RepoActor::CloneRepo", skip_all, fields(repo = %self.repo_details /*, gitdir = %self.repo_details.gitdir */))]
     fn handle(&mut self, _msg: CloneRepo, ctx: &mut Self::Context) -> Self::Result {
         let gitdir = self.repo_details.gitdir.clone();
         match git::repository::open(&self.repository, &self.repo_details, gitdir) {