Blink parity: preserve import indent in braced namespace; gate to 0.8% (#134)

Author: TomasVotruba

.github/workflows/blink_parity_mautic.yaml

@@ -95,7 +95,7 @@ jobs:
             - name: Compare the two trees
               run: |
                   # ratchet gate: fail once the differing share crosses this; lower it as parity improves
-                  MAX_DIFF_PERCENT=1.0
+                  MAX_DIFF_PERCENT=0.8
                   total=0
                   differ=0
                   differing_files=""

blink/internal/fixer/rules/imports.go

@@ -215,10 +215,18 @@ func (SingleLineAfterImports) Fix(s *tokens.Stream) bool {
 		if next.Kind == token.Punct && next.Value == "}" {
 			continue
 		}
-		if s.At(semi+1).Kind == token.Whitespace &&
-			hasNewline(s.At(semi+1).Value) && s.At(semi+1).Value != "\n\n" {
-			s.SetValue(semi+1, "\n\n")
-			changed = true
+		ws := s.At(semi + 1)
+		if ws.Kind == token.Whitespace && hasNewline(ws.Value) {
+			// preserve the import line's own indentation after the blank line, so a
+			// braced-namespace body keeps its level; a whitespace that already holds
+			// exactly one blank line (two newlines) is left untouched, as php-cs-fixer
+			if strings.Count(ws.Value, "\n") != 2 {
+				target := "\n\n" + indentBefore(s, i)
+				if ws.Value != target {
+					s.SetValue(semi+1, target)
+					changed = true
+				}
+			}
 		}
 	}
 	return changed

blink/internal/fixer/rules/rules_test.go

@@ -346,6 +346,17 @@ func TestSingleLineAfterImports(t *testing.T) {
 	if want := "<?php\nuse A;\nuse B;\n\nclass C {}"; !changed || got != want {
 		t.Fatalf("changed=%v got=%q want=%q", changed, got, want)
 	}
+
+	// inside a braced namespace the following line keeps its indentation
+	got, changed = apply(t, SingleLineAfterImports{}, "<?php\nnamespace N {\n    use A;\n    class C {}\n}")
+	if want := "<?php\nnamespace N {\n    use A;\n\n    class C {}\n}"; !changed || got != want {
+		t.Fatalf("braced: changed=%v got=%q want=%q", changed, got, want)
+	}
+
+	// a blank line that already exists is left untouched
+	if _, changed := apply(t, SingleLineAfterImports{}, "<?php\nnamespace N {\n    use A;\n\n    class C {}\n}"); changed {
+		t.Fatal("existing blank line after import must be a no-op")
+	}
 }
 
 func TestNoTrailingWhitespace(t *testing.T) {