verify that Id::prefix() makes use of the git configuration (#301)

git-repository/src/id.rs

@@ -1,4 +1,5 @@
 //!
+use std::convert::TryInto;
 use std::ops::Deref;
 
 use git_hash::{oid, ObjectId};
@@ -28,11 +29,22 @@ impl<'repo> Id<'repo> {
 
     /// Turn this object id into a shortened id with a length in hex as configured by `core.abbrev`.
     pub fn prefix(&self) -> Result<git_hash::Prefix, prefix::Error> {
-        // let hex_len = self.handle.config.get_int("core.abbrev")?;
+        let hex_len = self.repo.config_int("core.abbrev", 8);
+        let hex_len = hex_len.try_into().map_err(|_| prefix::Error::ConfigValue {
+            actual: hex_len,
+            max_range: self.inner.kind().len_in_hex(),
+            err: None,
+        })?;
+        let prefix =
+            git_odb::find::PotentialPrefix::new(self.inner, hex_len).map_err(|err| prefix::Error::ConfigValue {
+                actual: hex_len as i64,
+                max_range: self.inner.kind().len_in_hex(),
+                err: Some(err),
+            })?;
         Ok(self
             .repo
             .objects
-            .disambiguate_prefix(git_odb::find::PotentialPrefix::new(self.inner, 7)?)
+            .disambiguate_prefix(prefix)
             .map_err(crate::object::find::existing::OdbError::Find)?
             .ok_or(crate::object::find::existing::OdbError::NotFound { oid: self.inner })?)
     }
@@ -46,10 +58,13 @@ mod prefix {
     pub enum Error {
         #[error(transparent)]
         FindExisting(#[from] crate::object::find::existing::OdbError),
-        #[error(transparent)]
-        Config(#[from] crate::config::open::Error),
-        #[error(transparent)]
-        Prefix(#[from] git_hash::prefix::Error),
+        #[error("core.abbrev length was {}, but needs to be between 4 and {}", .actual, .max_range)]
+        ConfigValue {
+            #[source]
+            err: Option<git_hash::prefix::Error>,
+            actual: i64,
+            max_range: usize,
+        },
     }
 }
 

git-repository/src/repository/config.rs

@@ -3,7 +3,7 @@ impl crate::Repository {
     /// Return the integer value at `key` (like `core.abbrev`) or use the given `default` value if it isn't present.
     // TODO: figure out how to identify sub-sections, or how to design such an API. This is really just a first test.
     // TODO: tests
-    pub fn config_int(&self, key: &str, default: i64) -> i64 {
+    pub(crate) fn config_int(&self, key: &str, default: i64) -> i64 {
         let (section, key) = key.split_once('.').expect("valid section.key format");
         self.config
             .value::<git_config::values::Integer>(section, None, key)

git-repository/tests/easy/ext/reference.rs

@@ -3,7 +3,7 @@ mod set_namespace {
     use git_repository::refs::transaction::PreviousValue;
 
     fn easy_repo_rw() -> crate::Result<(git::Repository, tempfile::TempDir)> {
-        crate::repo_rw("make_references_repo.sh").map(|(r, d)| (r.to_thread_local(), d))
+        crate::repo_rw("make_references_repo.sh")
     }
 
     #[test]

git-repository/tests/easy/oid.rs → git-repository/tests/easy/id.rs

@@ -4,11 +4,26 @@ use std::cmp::Ordering;
 
 #[test]
 fn prefix() -> crate::Result {
-    let repo = crate::repo("make_repo_with_fork_and_dates.sh")?.to_thread_local();
+    let (repo, worktree_dir) = crate::repo_rw("make_repo_with_fork_and_dates.sh")?;
     let id = hex_to_id("288e509293165cb5630d08f4185bdf2445bf6170").attach(&repo);
     let prefix = id.prefix()?;
     assert_eq!(prefix.cmp_oid(&id), Ordering::Equal);
-    assert_eq!(prefix.hex_len(), 7, "preconfigured via core.abbrev");
+    assert_eq!(prefix.hex_len(), 8, "preconfigured via core.abbrev default value");
+
+    assert!(
+        std::process::Command::new("git")
+            .current_dir(worktree_dir.path())
+            .args(["config", "--int", "core.abbrev", "5"])
+            .status()?
+            .success(),
+        "set core abbrev value successfully"
+    );
+
+    let repo = git_repository::open(worktree_dir.path()).unwrap();
+    let id = id.detach().attach(&repo);
+    let prefix = id.prefix()?;
+    assert_eq!(prefix.cmp_oid(&id), Ordering::Equal);
+    assert_eq!(prefix.hex_len(), 5, "preconfigured via core.abbrev in the repo file");
     Ok(())
 }
 

git-repository/tests/easy/mod.rs

@@ -1,4 +1,4 @@
 mod ext;
+mod id;
 mod object;
-mod oid;
 mod reference;

git-repository/tests/repo.rs

@@ -8,9 +8,12 @@ fn repo(name: &str) -> crate::Result<ThreadSafeRepository> {
     Ok(ThreadSafeRepository::open(repo_path)?)
 }
 
-fn repo_rw(name: &str) -> crate::Result<(ThreadSafeRepository, tempfile::TempDir)> {
+fn repo_rw(name: &str) -> crate::Result<(git_repository::Repository, tempfile::TempDir)> {
     let repo_path = git_testtools::scripted_fixture_repo_writable(name)?;
-    Ok((ThreadSafeRepository::discover(repo_path.path())?, repo_path))
+    Ok((
+        ThreadSafeRepository::discover(repo_path.path())?.to_thread_local(),
+        repo_path,
+    ))
 }
 
 fn easy_repo_rw(name: &str) -> crate::Result<(Repository, tempfile::TempDir)> {