test: Add regression test for fallthrough behavior in if statements

README.md

@@ -25,7 +25,7 @@ go install github.com/keyskey/gobce/cmd/gobce@latest
 For CI and team-wide reproducibility, pin a version tag:
 
 ```bash
-go install github.com/keyskey/gobce/cmd/gobce@v0.1.0
+go install github.com/keyskey/gobce/cmd/gobce@v0.2.0
 ```
 
 ## Binary Distribution
@@ -37,7 +37,7 @@ Recommended archive set:
 - linux-arm64
 - linux-amd64
 
-Install from a prebuilt archive (example: `v0.1.0`, `darwin-arm64`):
+Install from a prebuilt archive (example: `v0.2.0`, `darwin-arm64`):
 
 ```bash
 curl -fsSL "https://raw.githubusercontent.com/keyskey/gobce/main/scripts/install.sh" | sh
@@ -46,7 +46,7 @@ curl -fsSL "https://raw.githubusercontent.com/keyskey/gobce/main/scripts/install
 Install a specific version:
 
 ```bash
-VERSION=v0.1.0 curl -fsSL "https://raw.githubusercontent.com/keyskey/gobce/main/scripts/install.sh" | sh
+VERSION=v0.2.0 curl -fsSL "https://raw.githubusercontent.com/keyskey/gobce/main/scripts/install.sh" | sh
 ```
 
 Install to a custom directory:
@@ -125,7 +125,7 @@ During the pre-1.0 phase, this project is versioned as `0.x` while coverage logi
 
 Please assume that interfaces and output formats may change between `0.x` minor versions.
 
-Version tags use the `vX.Y.Z` format (for example, `v0.1.0`).
+Version tags use the `vX.Y.Z` format (for example, `v0.2.0`).
 
 ## Release Flow
 
@@ -145,13 +145,13 @@ make tag-next TYPE=major
 ```
 
 ```bash
-git tag v0.1.0
-git push origin v0.1.0
+git tag v0.2.0
+git push origin v0.2.0
 ```
 
 After push:
 - GitHub Actions workflow `release` runs automatically
-- GitHub Release is created for `v0.1.0`
+- GitHub Release is created for `v0.2.0`
 - Release notes are generated from commit history
 - OS/arch archives and `checksums.txt` are uploaded
 

analyzer_test.go

@@ -210,6 +210,46 @@ func score(v int) int {
 	}
 }
 
+// Regression: coverprofile ends the if-body block at the closing "}", but the next
+// statement often starts on the following line; fallthrough must not require an exact
+// start position match with body.End().
+func TestAnalyzeIfWithoutElseFallthroughNextLine(t *testing.T) {
+	tmp := t.TempDir()
+	srcPath := filepath.Join(tmp, "sample.go")
+	src := `package sample
+
+func Get(v int) int {
+	if v > 10 {
+		return 1
+	}
+	return 0
+}
+`
+	if err := os.WriteFile(srcPath, []byte(src), 0o644); err != nil {
+		t.Fatalf("write source: %v", err)
+	}
+
+	coverPath := filepath.Join(tmp, "coverage.out")
+	coverage := strings.Join([]string{
+		"mode: set",
+		srcPath + ":3.23,4.13 1 1",
+		srcPath + ":4.13,6.3 1 0",
+		srcPath + ":7.2,7.10 1 1",
+	}, "\n")
+	if err := os.WriteFile(coverPath, []byte(coverage), 0o644); err != nil {
+		t.Fatalf("write coverage: %v", err)
+	}
+
+	result, err := Analyze(AnalyzeInput{CoverProfilePath: coverPath})
+	if err != nil {
+		t.Fatalf("analyze: %v", err)
+	}
+
+	if hasUncoveredBranchKind(result, "if_implicit_false_path") {
+		t.Fatalf("expected if_implicit_false_path covered when next-line fallthrough block has count")
+	}
+}
+
 func TestAnalyzeIfWithoutElseNonTerminatingBody(t *testing.T) {
 	tmp := t.TempDir()
 	srcPath := filepath.Join(tmp, "sample.go")

internal/analyzer/branches.go

@@ -148,17 +148,23 @@ func ifBodyTerminates(body *ast.BlockStmt) bool {
 	}
 }
 
+// fallthroughCovered reports whether execution can reach the first statement after body
+// (implicit else) according to coverage. The next cover block rarely starts at body.End()
+// (closing brace); it usually begins at the following statement, so we take the nearest
+// block in this file whose start is at or after body.End().
 func fallthroughCovered(blocks []coverageBlock, fset *token.FileSet, body *ast.BlockStmt) bool {
 	endPos := fset.Position(body.End())
-	for _, b := range blocks {
-		if b.Count <= 0 {
+	var nearest *coverageBlock
+	for i := range blocks {
+		b := &blocks[i]
+		if positionLess(b.StartLine, b.StartCol, endPos.Line, endPos.Column) {
 			continue
 		}
-		if b.StartLine == endPos.Line && b.StartCol == endPos.Column {
-			return true
+		if nearest == nil || positionLess(b.StartLine, b.StartCol, nearest.StartLine, nearest.StartCol) {
+			nearest = b
 		}
 	}
-	return false
+	return nearest != nil && nearest.Count > 0
 }
 
 func blockStmtCovered(blocks []coverageBlock, fset *token.FileSet, body *ast.BlockStmt) bool {