Throw an error if the steps has a invalid uses directive (#500)

* Throw an error if the steps has a invalid uses directive

* Refactor TestStepContextExecutor

pkg/runner/step_context.go

@@ -32,6 +32,12 @@ func (sc *StepContext) execJobContainer() common.Executor {
 	}
 }
 
+type formatError string
+
+func (e formatError) Error() string {
+	return fmt.Sprintf("Expected format {org}/{repo}[/path]@ref. Actual '%s' Input string was not in a correct format.", string(e))
+}
+
 // Executor for a step context
 func (sc *StepContext) Executor() common.Executor {
 	rc := sc.RunContext
@@ -57,14 +63,8 @@ func (sc *StepContext) Executor() common.Executor {
 		)
 	case model.StepTypeUsesActionRemote:
 		remoteAction := newRemoteAction(step.Uses)
-		if remoteAction.Ref == "" {
-			// GitHub's document[^] describes:
-			// > We strongly recommend that you include the version of
-			// > the action you are using by specifying a Git ref, SHA, or Docker tag number.
-			// Actually, the workflow stops if there is the uses directive that hasn't @ref.
-			// [^]: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions
-			msg := fmt.Sprintf("Expected format {org}/{repo}[/path]@ref. Actual '%s' Input string was not in a correct format.", step.Uses)
-			return common.NewErrorExecutor(fmt.Errorf("%s", msg))
+		if remoteAction == nil {
+			return common.NewErrorExecutor(formatError(step.Uses))
 		}
 		if remoteAction.IsCheckout() && rc.getGithubContext().isLocalCheckout(step) {
 			return func(ctx context.Context) error {
@@ -401,19 +401,22 @@ func (ra *remoteAction) IsCheckout() bool {
 }
 
 func newRemoteAction(action string) *remoteAction {
+	// GitHub's document[^] describes:
+	// > We strongly recommend that you include the version of
+	// > the action you are using by specifying a Git ref, SHA, or Docker tag number.
+	// Actually, the workflow stops if there is the uses directive that hasn't @ref.
+	// [^]: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions
 	r := regexp.MustCompile(`^([^/@]+)/([^/@]+)(/([^@]*))?(@(.*))?$`)
 	matches := r.FindStringSubmatch(action)
-
-	ra := new(remoteAction)
-	ra.Org = matches[1]
-	ra.Repo = matches[2]
-	if len(matches) >= 5 {
-		ra.Path = matches[4]
+	if len(matches) < 7 || matches[6] == "" {
+		return nil
 	}
-	if len(matches) >= 7 {
-		ra.Ref = matches[6]
+	return &remoteAction{
+		Org:  matches[1],
+		Repo: matches[2],
+		Path: matches[4],
+		Ref:  matches[6],
 	}
-	return ra
 }
 
 // https://github.com/nektos/act/issues/228#issuecomment-629709055

pkg/runner/step_context_test.go

@@ -0,0 +1,25 @@
+package runner
+
+import (
+	"context"
+	"testing"
+
+	"github.com/nektos/act/pkg/common"
+)
+
+func TestStepContextExecutor(t *testing.T) {
+	platforms := map[string]string{
+		"ubuntu-latest": "node:12.6-buster-slim",
+	}
+	tables := []TestJobFileInfo{
+		{"testdata", "uses-github-empty", "push", "Expected format {org}/{repo}[/path]@ref", platforms},
+		{"testdata", "uses-github-noref", "push", "Expected format {org}/{repo}[/path]@ref", platforms},
+		{"testdata", "uses-github-root", "push", "", platforms},
+		{"testdata", "uses-github-path", "push", "", platforms},
+	}
+	// These tests are sufficient to only check syntax.
+	ctx := common.WithDryrun(context.Background(), true)
+	for _, table := range tables {
+		runTestJobFile(ctx, t, table)
+	}
+}

pkg/runner/testdata/uses-github-empty/push.yml

@@ -0,0 +1,7 @@
+name: uses-github-empty
+on: push
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - name: empty

pkg/runner/testdata/uses-github-noref/push.yml

@@ -0,0 +1,7 @@
+name: uses-github-noref
+on: push
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout

pkg/runner/testdata/uses-github-path/push.yml

@@ -0,0 +1,7 @@
+name: uses-github-path
+on: push
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: sergioramos/yarn-actions/install@v6

pkg/runner/testdata/uses-github-root/push.yml

@@ -0,0 +1,7 @@
+name: uses-github-root
+on: push
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2