Use patience diff algorithm (microsoft#891)

Author: weswigham

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/dlclark/regexp2 v1.11.5
 	github.com/go-json-experiment/json v0.0.0-20250517221953-25912455fbc8
 	github.com/google/go-cmp v0.7.0
-	github.com/pkg/diff v0.0.0-20241224192749-4e6772a4315c
+	github.com/peter-evans/patience v0.3.0
 	golang.org/x/sync v0.14.0
 	golang.org/x/sys v0.33.0
 	gotest.tools/v3 v3.5.2

go.sum

@@ -12,8 +12,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/matryer/moq v0.5.3 h1:4femQCFmBUwFPYs8VfM5ID7AI67/DTEDRBbTtSWy7GU=
 github.com/matryer/moq v0.5.3/go.mod h1:8288Qkw7gMZhUP3cIN86GG7g5p9jRuZH8biXLW4RXvQ=
-github.com/pkg/diff v0.0.0-20241224192749-4e6772a4315c h1:8TRxBMS/YsupXoOiGKHr9ZOXo+5DezGWPgBAhBHEHto=
-github.com/pkg/diff v0.0.0-20241224192749-4e6772a4315c/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/peter-evans/patience v0.3.0 h1:rX0JdJeepqdQl1Sk9c9uvorjYYzL2TfgLX1adqYm9cA=
+github.com/peter-evans/patience v0.3.0/go.mod h1:Kmxu5sY1NmBLFSStvXjX1wS9mIv7wMcP/ubucyMOAu0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=

internal/testutil/baseline/baseline.go

@@ -11,8 +11,9 @@ import (
 
 	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/repo"
+	"github.com/microsoft/typescript-go/internal/stringutil"
 	"github.com/microsoft/typescript-go/internal/tspath"
-	"github.com/pkg/diff"
+	"github.com/peter-evans/patience"
 	"gotest.tools/v3/assert"
 )
 
@@ -102,21 +103,27 @@ func readFileOrNoContent(fileName string) string {
 	return string(content)
 }
 
+func diffText(oldName string, newName string, expected string, actual string) string {
+	lines := patience.Diff(stringutil.SplitLines(expected), stringutil.SplitLines(actual))
+	return patience.UnifiedDiffTextWithOptions(lines, patience.UnifiedDiffOptions{
+		Precontext:  3,
+		Postcontext: 3,
+		SrcHeader:   oldName,
+		DstHeader:   newName,
+	})
+}
+
 func getBaselineDiff(t *testing.T, actual string, expected string, fileName string, fixupOld func(string) string) string {
 	if fixupOld != nil {
 		expected = fixupOld(expected)
 	}
 	if actual == expected {
 		return NoContent
 	}
-	var b strings.Builder
-	if err := diff.Text("old."+fileName, "new."+fileName, expected, actual, &b); err != nil {
-		return fmt.Sprintf("failed to diff the actual and expected content: %v\n", err)
-	}
+	s := diffText("old."+fileName, "new."+fileName, expected, actual)
 
 	// Remove line numbers from unified diff headers; this avoids adding/deleting
 	// lines in our baselines from causing knock-on header changes later in the diff.
-	s := b.String()
 
 	aCurLine := 1
 	bCurLine := 1

testdata/baselines/reference/submodule/compiler/2dArrays.js.diff

@@ -2,7 +2,7 @@
 +++ new.2dArrays.js
 @@= skipped -17, +17 lines =@@
  }
- 
+
  //// [2dArrays.js]
 -var Cell = /** @class */ (function () {
 -    function Cell() {
@@ -32,4 +32,4 @@
 -    return Board;
 -}());
 +    }
-+}
++}

testdata/baselines/reference/submodule/compiler/2dArrays.symbols.diff

@@ -2,29 +2,29 @@
 +++ new.2dArrays.symbols
 @@= skipped -8, +8 lines =@@
  >Ship : Symbol(Ship, Decl(2dArrays.ts, 1, 1))
- 
+
      isSunk: boolean;
 ->isSunk : Symbol(Ship.isSunk, Decl(2dArrays.ts, 3, 12))
 +>isSunk : Symbol(isSunk, Decl(2dArrays.ts, 3, 12))
  }
- 
+
  class Board {
  >Board : Symbol(Board, Decl(2dArrays.ts, 5, 1))
- 
+
      ships: Ship[];
 ->ships : Symbol(Board.ships, Decl(2dArrays.ts, 7, 13))
 +>ships : Symbol(ships, Decl(2dArrays.ts, 7, 13))
  >Ship : Symbol(Ship, Decl(2dArrays.ts, 1, 1))
- 
+
      cells: Cell[];
 ->cells : Symbol(Board.cells, Decl(2dArrays.ts, 8, 18))
 +>cells : Symbol(cells, Decl(2dArrays.ts, 8, 18))
  >Cell : Symbol(Cell, Decl(2dArrays.ts, 0, 0))
- 
+
      private allShipsSunk() {
 ->allShipsSunk : Symbol(Board.allShipsSunk, Decl(2dArrays.ts, 9, 18))
 +>allShipsSunk : Symbol(allShipsSunk, Decl(2dArrays.ts, 9, 18))
- 
+
          return this.ships.every(function (val) { return val.isSunk; });
 ->this.ships.every : Symbol(Array.every, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
 ->this.ships : Symbol(Board.ships, Decl(2dArrays.ts, 7, 13))
@@ -33,13 +33,15 @@
  >this : Symbol(Board, Decl(2dArrays.ts, 5, 1))
 ->ships : Symbol(Board.ships, Decl(2dArrays.ts, 7, 13))
 ->every : Symbol(Array.every, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
+->val : Symbol(val, Decl(2dArrays.ts, 12, 42))
+->val.isSunk : Symbol(Ship.isSunk, Decl(2dArrays.ts, 3, 12))
+->val : Symbol(val, Decl(2dArrays.ts, 12, 42))
+->isSunk : Symbol(Ship.isSunk, Decl(2dArrays.ts, 3, 12))
 +>ships : Symbol(ships, Decl(2dArrays.ts, 7, 13))
 +>every : Symbol(every, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
- >val : Symbol(val, Decl(2dArrays.ts, 12, 42))
-->val.isSunk : Symbol(Ship.isSunk, Decl(2dArrays.ts, 3, 12))
++>val : Symbol(val, Decl(2dArrays.ts, 12, 42))
 +>val.isSunk : Symbol(isSunk, Decl(2dArrays.ts, 3, 12))
- >val : Symbol(val, Decl(2dArrays.ts, 12, 42))
-->isSunk : Symbol(Ship.isSunk, Decl(2dArrays.ts, 3, 12))
++>val : Symbol(val, Decl(2dArrays.ts, 12, 42))
 +>isSunk : Symbol(isSunk, Decl(2dArrays.ts, 3, 12))
      }    
- }
+ }

testdata/baselines/reference/submodule/compiler/APILibCheck.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APILibCheck.errors.txt
 +++ new.APILibCheck.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +index.ts(1,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +index.ts(2,29): error TS2307: Cannot find module 'typescript-internal' or its corresponding type declarations.
 +index.ts(3,34): error TS2307: Cannot find module 'tsserverlibrary' or its corresponding type declarations.
@@ -46,4 +45,4 @@
 +        "name": "tsserverlibrary-internal",
 +        "types": "/.ts/tsserverlibrary.internal.d.ts"
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_Watch.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_Watch.errors.txt
 +++ new.APISample_Watch.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_Watch.ts(11,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +APISample_Watch.ts(14,27): error TS7006: Parameter 'path' implicitly has an 'any' type.
 +APISample_Watch.ts(45,61): error TS7006: Parameter 'options' implicitly has an 'any' type.
@@ -104,4 +103,4 @@
 +        "name": "typescript",
 +        "types": "/.ts/typescript.d.ts"
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_Watch.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_Watch.js
 +++ new.APISample_Watch.js
 @@= skipped -84, +84 lines =@@
- 
+
  //// [APISample_Watch.js]
  "use strict";
 -/*
@@ -47,4 +47,4 @@
 +    host.afterProgramCreate = program => {
          console.log("** We finished making the program! **");
          origPostProgramCreate(program);
-     };
+     };

testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_WatchWithDefaults.errors.txt
 +++ new.APISample_WatchWithDefaults.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_WatchWithDefaults.ts(8,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +APISample_WatchWithDefaults.ts(32,27): error TS7006: Parameter 'rootNames' implicitly has an 'any' type.
 +APISample_WatchWithDefaults.ts(32,38): error TS7006: Parameter 'options' implicitly has an 'any' type.
@@ -77,4 +76,4 @@
 +        "name": "typescript",
 +        "types": "/.ts/typescript.d.ts"
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_WatchWithDefaults.js
 +++ new.APISample_WatchWithDefaults.js
 @@= skipped -57, +57 lines =@@
- 
+
  //// [APISample_WatchWithDefaults.js]
  "use strict";
 -/*
@@ -38,4 +38,4 @@
 +    host.afterProgramCreate = program => {
          console.log("** We finished making the program! **");
          origPostProgramCreate(program);
-     };
+     };

testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_WatchWithOwnWatchHost.errors.txt
 +++ new.APISample_WatchWithOwnWatchHost.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_WatchWithOwnWatchHost.ts(8,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +APISample_WatchWithOwnWatchHost.ts(22,32): error TS7006: Parameter 'options' implicitly has an 'any' type.
 +APISample_WatchWithOwnWatchHost.ts(39,27): error TS7006: Parameter 'rootNames' implicitly has an 'any' type.
@@ -87,4 +86,4 @@
 +        "name": "typescript",
 +        "types": "/.ts/typescript.d.ts"
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_WatchWithOwnWatchHost.js
 +++ new.APISample_WatchWithOwnWatchHost.js
 @@= skipped -64, +64 lines =@@
- 
+
  //// [APISample_WatchWithOwnWatchHost.js]
  "use strict";
 -/*
@@ -49,4 +49,4 @@
 +    host.afterProgramCreate = program => {
          console.log("** We finished making the program! **");
          origPostProgramCreate(program);
-     };
+     };

testdata/baselines/reference/submodule/compiler/APISample_compile.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_compile.errors.txt
 +++ new.APISample_compile.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_compile.ts(11,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +APISample_compile.ts(19,28): error TS7006: Parameter 'diagnostic' implicitly has an 'any' type.
 +
@@ -55,4 +54,4 @@
 +        "name": "typescript",
 +        "types": "/.ts/typescript.d.ts"
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_compile.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_compile.js
 +++ new.APISample_compile.js
 @@= skipped -47, +47 lines =@@
- 
+
  //// [APISample_compile.js]
  "use strict";
 -/*
@@ -34,4 +34,4 @@
 +    console.log(`Process exiting with code '${exitCode}'.`);
      process.exit(exitCode);
  }
- compile(process.argv.slice(2), {
+ compile(process.argv.slice(2), {

testdata/baselines/reference/submodule/compiler/APISample_jsdoc.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_jsdoc.errors.txt
 +++ new.APISample_jsdoc.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_jsdoc.ts(10,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +APISample_jsdoc.ts(26,47): error TS7006: Parameter 'comment' implicitly has an 'any' type.
 +APISample_jsdoc.ts(31,20): error TS7006: Parameter 'doc' implicitly has an 'any' type.
@@ -133,4 +132,4 @@
 +        tags.push(ts.getJSDocTemplateTag(node));
 +        return tags;
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_jsdoc.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_jsdoc.js
 +++ new.APISample_jsdoc.js
 @@= skipped -122, +122 lines =@@
- 
+
  //// [APISample_jsdoc.js]
  "use strict";
 -/*
@@ -104,4 +104,4 @@
 +    const type = ts.getJSDocTypeTag(node);
      if (type) {
          tags.push(type);
-     }
+     }

testdata/baselines/reference/submodule/compiler/APISample_linter.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_linter.errors.txt
 +++ new.APISample_linter.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_linter.ts(11,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +
 +
@@ -78,4 +77,4 @@
 +        // delint it
 +        delint(sourceFile);
 +    });
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_linter.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_linter.js
 +++ new.APISample_linter.js
 @@= skipped -73, +73 lines =@@
- 
+
  //// [APISample_linter.js]
  "use strict";
 -/*
@@ -53,4 +53,4 @@
 +    let sourceFile = ts.createSourceFile(fileName, readFileSync(fileName).toString(), ts.ScriptTarget.ES2015, /*setParentNodes */ true);
      // delint it
      delint(sourceFile);
- });
+ });

testdata/baselines/reference/submodule/compiler/APISample_parseConfig.errors.txt.diff

@@ -1,8 +1,7 @@
 --- old.APISample_parseConfig.errors.txt
 +++ new.APISample_parseConfig.errors.txt
-@@= skipped -0, +-1 lines =@@
+@@= skipped -0, +0 lines =@@
 -<no content>
-@@= skipped --1, +1 lines =@@
 +APISample_parseConfig.ts(11,21): error TS2307: Cannot find module 'typescript' or its corresponding type declarations.
 +
 +
@@ -50,4 +49,4 @@
 +        "name": "typescript",
 +        "types": "/.ts/typescript.d.ts"
 +    }
-+    
++    

testdata/baselines/reference/submodule/compiler/APISample_parseConfig.js.diff

@@ -1,7 +1,7 @@
 --- old.APISample_parseConfig.js
 +++ new.APISample_parseConfig.js
 @@= skipped -45, +45 lines =@@
- 
+
  //// [APISample_parseConfig.js]
  "use strict";
 -/*
@@ -37,4 +37,4 @@
 +        for (const err of settings.errors) {
              printError(err);
          }
-         return undefined;
+         return undefined;