test: add unit tests for JS request/response objects and error patterns

- Add unit tests for Request (method, url, headers) and Response (status, statusText, ok, headers)
- Add test for {"error": "..."} pattern in TransformError
- Add test for infinite loop timeout (ErrJSTimeout)
- Fix lint errors in config_test.go (os.Remove and tmpFile.Close error handling)
- Fix sealed object tests to verify silent ignoring behavior instead of expecting errors

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mpyw

internal/config/config_test.go

@@ -435,7 +435,7 @@ func TestParseFile(t *testing.T) {
 		// Create a temporary file
 		tmpFile, err := os.CreateTemp("", "config-*.yaml")
 		require.NoError(t, err)
-		defer os.Remove(tmpFile.Name())
+		defer func() { _ = os.Remove(tmpFile.Name()) }()
 
 		content := `
 queries:
@@ -447,7 +447,7 @@ queries:
 `
 		_, err = tmpFile.WriteString(content)
 		require.NoError(t, err)
-		tmpFile.Close()
+		require.NoError(t, tmpFile.Close())
 
 		cfg, err := ParseFile(tmpFile.Name())
 		require.NoError(t, err)

internal/js/apply_test.go

@@ -1,6 +1,7 @@
 package js
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -287,3 +288,21 @@ func TestApplyPostToAllRows(t *testing.T) {
 		assert.Equal(t, int64(2), resultMap["total"])
 	})
 }
+
+func TestJSTimeout(t *testing.T) {
+	t.Run("infinite loop times out", func(t *testing.T) {
+		// This test verifies that infinite loops are interrupted
+		// Note: JSTimeout is 5 seconds by default
+		transformer, err := CompilePre(`while(true) {} return input`)
+		require.NoError(t, err)
+
+		_, err = transformer.ApplyPre(
+			map[string]any{},
+			"SELECT 1",
+			map[string]any{},
+			nil,
+		)
+		require.Error(t, err)
+		assert.True(t, errors.Is(err, ErrJSTimeout), "expected timeout error, got: %v", err)
+	})
+}

internal/js/error_test.go

@@ -21,6 +21,14 @@ func TestTransformError(t *testing.T) {
 		assert.Equal(t, "validation error", err.Error())
 	})
 
+	t.Run("object body with error key", func(t *testing.T) {
+		err := &TransformError{
+			Status: 400,
+			Body:   map[string]any{"error": "something went wrong", "code": "ERR001"},
+		}
+		assert.Equal(t, "something went wrong", err.Error())
+	})
+
 	t.Run("object body without message", func(t *testing.T) {
 		err := &TransformError{
 			Status: 400,
@@ -147,3 +155,18 @@ func TestParseJSError_ThrownString(t *testing.T) {
 		assert.Equal(t, "simple error message", transformErr.Body)
 	})
 }
+
+func TestParseJSError_ErrorKey(t *testing.T) {
+	t.Run("body with error key", func(t *testing.T) {
+		transformer, err := CompilePre(`throw { status: 400, body: { error: "something went wrong" } }`)
+		require.NoError(t, err)
+
+		_, err = transformer.ApplyMock(nil, "", nil, nil)
+		require.Error(t, err)
+
+		var transformErr *TransformError
+		require.ErrorAs(t, err, &transformErr)
+		assert.Equal(t, 400, transformErr.Status)
+		assert.Equal(t, "something went wrong", transformErr.Error())
+	})
+}

internal/js/request_test.go

@@ -0,0 +1,94 @@
+package js
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/dop251/goja"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRequest(t *testing.T) {
+	req := httptest.NewRequest(http.MethodPost, "/test/path?foo=bar", nil)
+	req.Header.Set("X-Custom", "value")
+	req.Header.Set("Content-Type", "application/json")
+
+	r := NewRequest(req)
+
+	t.Run("Method", func(t *testing.T) {
+		assert.Equal(t, "POST", r.Method())
+	})
+
+	t.Run("URL", func(t *testing.T) {
+		assert.Equal(t, "/test/path?foo=bar", r.URL())
+	})
+
+	t.Run("Headers", func(t *testing.T) {
+		h := r.Headers()
+		require.NotNil(t, h)
+		assert.Equal(t, "value", h.Get("X-Custom"))
+		assert.Equal(t, "application/json", h.Get("Content-Type"))
+	})
+}
+
+func TestRequest_ToJSObject(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/api/users?id=123", nil)
+	req.Header.Set("Authorization", "Bearer token")
+
+	r := NewRequest(req)
+	vm := goja.New()
+	obj := r.ToJSObject(vm)
+
+	err := vm.Set("request", obj)
+	require.NoError(t, err)
+
+	t.Run("method property", func(t *testing.T) {
+		result, err := vm.RunString(`request.method`)
+		require.NoError(t, err)
+		assert.Equal(t, "GET", result.String())
+	})
+
+	t.Run("url property", func(t *testing.T) {
+		result, err := vm.RunString(`request.url`)
+		require.NoError(t, err)
+		assert.Equal(t, "/api/users?id=123", result.String())
+	})
+
+	t.Run("headers.get()", func(t *testing.T) {
+		result, err := vm.RunString(`request.headers.get("Authorization")`)
+		require.NoError(t, err)
+		assert.Equal(t, "Bearer token", result.String())
+	})
+
+	t.Run("headers.has()", func(t *testing.T) {
+		result, err := vm.RunString(`request.headers.has("Authorization")`)
+		require.NoError(t, err)
+		assert.True(t, result.ToBoolean())
+
+		result, err = vm.RunString(`request.headers.has("X-Missing")`)
+		require.NoError(t, err)
+		assert.False(t, result.ToBoolean())
+	})
+
+	t.Run("request is sealed - new property ignored", func(t *testing.T) {
+		// Sealed objects silently ignore new property assignments in non-strict mode
+		_, err := vm.RunString(`request.newProp = "test"`)
+		require.NoError(t, err)
+
+		result, err := vm.RunString(`request.newProp`)
+		require.NoError(t, err)
+		assert.True(t, goja.IsUndefined(result)) // Property was not added
+	})
+
+	t.Run("method is read-only - assignment ignored", func(t *testing.T) {
+		// Read-only properties silently ignore assignments in non-strict mode
+		_, err := vm.RunString(`request.method = "PUT"`)
+		require.NoError(t, err)
+
+		result, err := vm.RunString(`request.method`)
+		require.NoError(t, err)
+		assert.Equal(t, "GET", result.String()) // Value unchanged
+	})
+}