Add CI example/fuzz gates and fix parser panic

Author: mgomes

.github/workflows/test.yml

@@ -56,3 +56,23 @@ jobs:
         if: runner.os == 'Windows'
         shell: pwsh
         run: golangci-lint run --timeout=10m --out-format=colored-line-number
+
+  quality-gates:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Gate examples coverage
+        run: go test ./vibes -run 'TestExamples|TestDocsExampleSnippetsCompile'
+
+      - name: Gate parser fuzz target
+        run: go test ./vibes -run '^$' -fuzz=FuzzCompileScriptDoesNotPanic -fuzztime=5s
+
+      - name: Gate runtime fuzz target
+        run: go test ./vibes -run '^$' -fuzz=FuzzRuntimeEdgeCasesDoNotPanic -fuzztime=5s

ROADMAP.md

@@ -341,7 +341,7 @@ Goal: improve day-to-day developer productivity and interpreter robustness.
 
 - [ ] Tooling commands are documented and stable.
 - [ ] Performance regressions are tracked with benchmarks.
-- [ ] CI includes example and fuzz coverage gates.
+- [x] CI includes example and fuzz coverage gates.
 
 ---
 

vibes/parser.go

@@ -691,6 +691,9 @@ func (p *parser) parseExpression(precedence int) Expression {
 	}
 
 	left := prefix()
+	if left == nil {
+		return nil
+	}
 
 	for p.peekToken.Type != tokenEOF && precedence < p.peekPrecedence() {
 		infix := p.infixFns[p.peekToken.Type]
@@ -699,6 +702,9 @@ func (p *parser) parseExpression(precedence int) Expression {
 		}
 		p.nextToken()
 		left = infix(left)
+		if left == nil {
+			return nil
+		}
 	}
 
 	return left
@@ -948,6 +954,9 @@ func (p *parser) parseRangeExpression(left Expression) Expression {
 }
 
 func (p *parser) parseCallExpression(function Expression) Expression {
+	if function == nil {
+		return nil
+	}
 	expr := &CallExpr{Callee: function, position: function.Pos()}
 	args := []Expression{}
 	kwargs := []KeywordArg{}

vibes/runtime_test.go

@@ -28,6 +28,20 @@ func callFunc(t *testing.T, script *Script, name string, args []Value) Value {
 	return result
 }
 
+func TestCompileMalformedCallTargetDoesNotPanic(t *testing.T) {
+	engine := MustNewEngine(Config{})
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("compile panicked: %v", r)
+		}
+	}()
+
+	_, err := engine.Compile(`be(in (000000000`)
+	if err == nil {
+		t.Fatalf("expected compile error for malformed input")
+	}
+}
+
 func TestHashMergeAndKeys(t *testing.T) {
 	script := compileScript(t, `
     def merged()

vibes/testdata/fuzz/FuzzCompileScriptDoesNotPanic/1bb2e90f05d4df7d

@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("be(in (000000000")