Merge pull request #2288 from cruessler/update-imara-diff

Update to `imara-diff` 0.2 in diff slider test

Author: Byron

gix-diff/tests/diff/blob/slider.rs

@@ -1,11 +1,11 @@
-use gix_diff::blob::intern::TokenSource;
-use gix_diff::blob::unified_diff::ContextSize;
-use gix_diff::blob::{Algorithm, UnifiedDiff};
+use gix_object::bstr::ByteSlice;
 use gix_testtools::bstr::{BString, ByteVec};
 use pretty_assertions::StrComparison;
 
 #[test]
-fn baseline() -> gix_testtools::Result {
+fn baseline_v1() -> gix_testtools::Result {
+    use gix_diff::blob::{unified_diff::ContextSize, UnifiedDiff};
+
     let worktree_path = gix_testtools::scripted_fixture_read_only_standalone("make_diff_for_sliders_repo.sh")?;
     let asset_dir = worktree_path.join("assets");
 
@@ -15,30 +15,16 @@ fn baseline() -> gix_testtools::Result {
 
     for entry in dir {
         let entry = entry?;
-        let file_name = entry.file_name().into_string().expect("to be string");
-
-        if !file_name.ends_with(".baseline") {
+        let Some(baseline::DirEntry {
+            file_name,
+            algorithm,
+            old_data,
+            new_data,
+        }) = baseline::parse_dir_entry(&asset_dir, &entry.file_name())?
+        else {
             continue;
-        }
-
-        let parts: Vec<_> = file_name.split('.').collect();
-        let [name, algorithm, ..] = parts[..] else {
-            unreachable!()
-        };
-        let algorithm = match algorithm {
-            "myers" => Algorithm::Myers,
-            "histogram" => Algorithm::Histogram,
-            _ => unreachable!(),
-        };
-
-        let parts: Vec<_> = name.split('-').collect();
-        let [old_blob_id, new_blob_id] = parts[..] else {
-            unreachable!();
         };
 
-        let old_data = std::fs::read(asset_dir.join(format!("{old_blob_id}.blob")))?;
-        let new_data = std::fs::read(asset_dir.join(format!("{new_blob_id}.blob")))?;
-
         let interner = gix_diff::blob::intern::InternedInput::new(
             tokens_for_diffing(old_data.as_slice()),
             tokens_for_diffing(new_data.as_slice()),
@@ -70,17 +56,74 @@ fn baseline() -> gix_testtools::Result {
             })
             .to_string();
 
-        let baseline = baseline
-            .fold(BString::default(), |mut acc, diff_hunk| {
-                acc.push_str(diff_hunk.header.to_string().as_str());
-                acc.push(b'\n');
+        let baseline = baseline.fold_to_unidiff().to_string();
+        let actual_matches_baseline = actual == baseline;
+        diffs.push((actual, baseline, actual_matches_baseline, file_name));
+    }
 
-                acc.extend_from_slice(&diff_hunk.lines);
+    if diffs.is_empty() {
+        eprintln!("Slider baseline isn't setup - look at ./gix-diff/tests/README.md for instructions");
+    }
 
-                acc
-            })
+    assert_diffs(&diffs);
+
+    Ok(())
+}
+
+fn tokens_for_diffing(data: &[u8]) -> impl gix_diff::blob::intern::TokenSource<Token = &[u8]> {
+    gix_diff::blob::sources::byte_lines(data)
+}
+
+#[test]
+fn baseline_v2() -> gix_testtools::Result {
+    use gix_diff::blob::v2::{Algorithm, BasicLineDiffPrinter, Diff, InternedInput, UnifiedDiffConfig};
+
+    let worktree_path = gix_testtools::scripted_fixture_read_only_standalone("make_diff_for_sliders_repo.sh")?;
+    let asset_dir = worktree_path.join("assets");
+
+    let dir = std::fs::read_dir(&worktree_path)?;
+
+    let mut diffs = Vec::new();
+
+    for entry in dir {
+        let entry = entry?;
+        let Some(baseline::DirEntry {
+            file_name,
+            algorithm,
+            old_data,
+            new_data,
+        }) = baseline::parse_dir_entry(&asset_dir, &entry.file_name())?
+        else {
+            continue;
+        };
+
+        let input = InternedInput::new(
+            old_data.to_str().expect("BUG: we don't have non-ascii here"),
+            new_data.to_str().expect("BUG: we don't have non-ascii here"),
+        );
+        let algorithm = match algorithm {
+            gix_diff::blob::Algorithm::Myers => Algorithm::Myers,
+            gix_diff::blob::Algorithm::Histogram => Algorithm::Histogram,
+            gix_diff::blob::Algorithm::MyersMinimal => Algorithm::MyersMinimal,
+        };
+
+        let mut diff = Diff::compute(algorithm, &input);
+        diff.postprocess_lines(&input);
+
+        let actual = diff
+            .unified_diff(
+                &BasicLineDiffPrinter(&input.interner),
+                UnifiedDiffConfig::default(),
+                &input,
+            )
             .to_string();
 
+        let baseline_path = worktree_path.join(&file_name);
+        let baseline = std::fs::read(baseline_path)?;
+        let baseline = baseline::Baseline::new(&baseline);
+
+        let baseline = baseline.fold_to_unidiff().to_string();
+
         let actual_matches_baseline = actual == baseline;
         diffs.push((actual, baseline, actual_matches_baseline, file_name));
     }
@@ -89,6 +132,11 @@ fn baseline() -> gix_testtools::Result {
         eprintln!("Slider baseline isn't setup - look at ./gix-diff/tests/README.md for instructions");
     }
 
+    assert_diffs(&diffs);
+    Ok(())
+}
+
+fn assert_diffs(diffs: &[(String, String, bool, String)]) {
     let total_diffs = diffs.len();
     let matching_diffs = diffs
         .iter()
@@ -115,20 +163,16 @@ fn baseline() -> gix_testtools::Result {
             )
         }
     );
-
-    Ok(())
-}
-
-fn tokens_for_diffing(data: &[u8]) -> impl TokenSource<Token = &[u8]> {
-    gix_diff::blob::sources::byte_lines(data)
 }
 
 mod baseline {
-    use gix_object::bstr::ByteSlice;
-    use std::iter::Peekable;
-
     use gix_diff::blob::unified_diff::{ConsumeHunk, HunkHeader};
+    use gix_diff::blob::Algorithm;
     use gix_object::bstr::{self, BString};
+    use gix_object::bstr::{ByteSlice, ByteVec};
+    use std::ffi::OsStr;
+    use std::iter::Peekable;
+    use std::path::Path;
 
     static START_OF_HEADER: &[u8; 4] = b"@@ -";
 
@@ -193,6 +237,20 @@ mod baseline {
         }
     }
 
+    impl Baseline<'_> {
+        /// Converts all baseline [`DiffHunk`]s into a single unified diff format string.
+        pub fn fold_to_unidiff(self) -> BString {
+            self.fold(BString::default(), |mut acc, diff_hunk| {
+                acc.push_str(diff_hunk.header.to_string().as_str());
+                acc.push(b'\n');
+
+                acc.extend_from_slice(&diff_hunk.lines);
+
+                acc
+            })
+        }
+    }
+
     impl Iterator for Baseline<'_> {
         type Item = DiffHunk;
 
@@ -285,4 +343,45 @@ mod baseline {
             .parse::<u32>()
             .expect("to be a number")
     }
+
+    pub struct DirEntry {
+        pub file_name: String,
+        pub algorithm: Algorithm,
+        pub old_data: Vec<u8>,
+        pub new_data: Vec<u8>,
+    }
+
+    /// Returns `None` if the file isn't a baseline entry.
+    pub fn parse_dir_entry(asset_dir: &Path, file_name: &OsStr) -> std::io::Result<Option<DirEntry>> {
+        let file_name = file_name.to_str().expect("ascii filename").to_owned();
+
+        if !file_name.ends_with(".baseline") {
+            return Ok(None);
+        }
+
+        let parts: Vec<_> = file_name.split('.').collect();
+        let [name, algorithm, ..] = parts[..] else {
+            unreachable!("BUG: Need file named '<name>.<algorithm>'")
+        };
+        let algorithm = match algorithm {
+            "myers" => Algorithm::Myers,
+            "histogram" => Algorithm::Histogram,
+            other => unreachable!("BUG: '{other}' is not a supported algorithm"),
+        };
+
+        let parts: Vec<_> = name.split('-').collect();
+        let [old_blob_id, new_blob_id] = parts[..] else {
+            unreachable!("BUG: name part of filename must be '<old_blob_id>-<new_blob_id>'");
+        };
+
+        let old_data = std::fs::read(asset_dir.join(format!("{old_blob_id}.blob")))?;
+        let new_data = std::fs::read(asset_dir.join(format!("{new_blob_id}.blob")))?;
+        Ok(DirEntry {
+            file_name,
+            algorithm,
+            old_data,
+            new_data,
+        }
+        .into())
+    }
 }