Fix github workflow matrix generation

cmd/build_test_matrix/main.go

@@ -36,7 +36,7 @@ type TestSuitePair struct {
 }
 
 func main() {
-	githubActionMatrix, err := getGithubActionMatrixForTests(e2eTestDirectory, getTestFunctionToRun(), getExcludedTestFunctions())
+	githubActionMatrix, err := getGithubActionMatrixForTests(e2eTestDirectory, getTestToRun(), getTestEntrypointToRun(), getExcludedTestFunctions())
 	if err != nil {
 		fmt.Printf("error generating github action json: %s", err)
 		os.Exit(1)
@@ -50,16 +50,26 @@ func main() {
 	fmt.Println(string(ghBytes))
 }
 
-// getTestFunctionToRun returns the specified test function to run if present, otherwise
+// getTestEntrypointToRun returns the specified test function to run if present, otherwise
 // it returns an empty string which will result in running all test suites.
-func getTestFunctionToRun() string {
+func getTestEntrypointToRun() string {
 	testSuite, ok := os.LookupEnv(testEntryPointEnv)
 	if !ok {
 		return ""
 	}
 	return testSuite
 }
 
+// getTestToRun returns the specified test function to run if present.
+// If specified, only this test will be run.
+func getTestToRun() string {
+	testName, ok := os.LookupEnv(testNameEnv)
+	if !ok {
+		return ""
+	}
+	return testName
+}
+
 // getExcludedTestFunctions returns a list of test functions that we don't want to run.
 func getExcludedTestFunctions() []string {
 	exclusions, ok := os.LookupEnv(testExclusionsEnv)
@@ -81,7 +91,7 @@ func contains(s string, items []string) bool {
 // getGithubActionMatrixForTests returns a json string representing the contents that should go in the matrix
 // field in a github action workflow. This string can be used with `fromJSON(str)` to dynamically build
 // the workflow matrix to include all E2E tests under the e2eRootDirectory directory.
-func getGithubActionMatrixForTests(e2eRootDirectory, suite string, exlcudedItems []string) (GithubActionTestMatrix, error) {
+func getGithubActionMatrixForTests(e2eRootDirectory, testName string, suite string, excludedItems []string) (GithubActionTestMatrix, error) {
 	testSuiteMapping := map[string][]string{}
 	fset := token.NewFileSet()
 	err := filepath.Walk(e2eRootDirectory, func(path string, info fs.FileInfo, err error) error {
@@ -104,14 +114,11 @@ func getGithubActionMatrixForTests(e2eRootDirectory, suite string, exlcudedItems
 			return fmt.Errorf("failed extracting test suite name and test cases: %s", err)
 		}
 
-		testName := os.Getenv(testNameEnv)
 		if testName != "" && contains(testName, testCases) {
 			testCases = []string{testName}
-		} else if testName != "" {
-			return fmt.Errorf("failed to find test case: %s", testName)
 		}
 
-		if contains(suiteNameForFile, exlcudedItems) {
+		if contains(suiteNameForFile, excludedItems) {
 			return nil
 		}
 
@@ -138,6 +145,10 @@ func getGithubActionMatrixForTests(e2eRootDirectory, suite string, exlcudedItems
 		}
 	}
 
+	if testName != "" && len(gh.Include) != 1 {
+		return GithubActionTestMatrix{}, fmt.Errorf("expected exactly 1 test in the output matrix but got %d", len(gh.Include))
+	}
+
 	return gh, nil
 }
 

cmd/build_test_matrix/main_test.go

@@ -19,15 +19,15 @@ const (
 func TestGetGithubActionMatrixForTests(t *testing.T) {
 	t.Run("empty dir does not fail", func(t *testing.T) {
 		testingDir := t.TempDir()
-		_, err := getGithubActionMatrixForTests(testingDir, "", nil)
+		_, err := getGithubActionMatrixForTests(testingDir, "", "", nil)
 		assert.NoError(t, err)
 	})
 
 	t.Run("only test functions are picked up", func(t *testing.T) {
 		testingDir := t.TempDir()
 		createFileWithTestSuiteAndTests(t, "FeeMiddlewareTestSuite", "TestA", "TestB", testingDir, goTestFileNameOne)
 
-		gh, err := getGithubActionMatrixForTests(testingDir, "", nil)
+		gh, err := getGithubActionMatrixForTests(testingDir, "", "", nil)
 		assert.NoError(t, err)
 
 		expected := GithubActionTestMatrix{
@@ -50,7 +50,7 @@ func TestGetGithubActionMatrixForTests(t *testing.T) {
 		createFileWithTestSuiteAndTests(t, "FeeMiddlewareTestSuite", "TestA", "TestB", testingDir, goTestFileNameOne)
 		createFileWithTestSuiteAndTests(t, "TransferTestSuite", "TestC", "TestD", testingDir, goTestFileNameTwo)
 
-		gh, err := getGithubActionMatrixForTests(testingDir, "", nil)
+		gh, err := getGithubActionMatrixForTests(testingDir, "", "", nil)
 		assert.NoError(t, err)
 
 		expected := GithubActionTestMatrix{
@@ -77,11 +77,39 @@ func TestGetGithubActionMatrixForTests(t *testing.T) {
 		assertGithubActionTestMatricesEqual(t, expected, gh)
 	})
 
+	t.Run("single test can be specified", func(t *testing.T) {
+		testingDir := t.TempDir()
+		createFileWithTestSuiteAndTests(t, "FeeMiddlewareTestSuite", "TestA", "TestB", testingDir, goTestFileNameOne)
+		createFileWithTestSuiteAndTests(t, "TransferTestSuite", "TestC", "TestD", testingDir, goTestFileNameTwo)
+
+		gh, err := getGithubActionMatrixForTests(testingDir, "TestA", "TestFeeMiddlewareTestSuite", nil)
+		assert.NoError(t, err)
+
+		expected := GithubActionTestMatrix{
+			Include: []TestSuitePair{
+				{
+					EntryPoint: "TestFeeMiddlewareTestSuite",
+					Test:       "TestA",
+				},
+			},
+		}
+
+		assertGithubActionTestMatricesEqual(t, expected, gh)
+	})
+
+	t.Run("error if single test doesn't exist", func(t *testing.T) {
+		testingDir := t.TempDir()
+		createFileWithTestSuiteAndTests(t, "FeeMiddlewareTestSuite", "TestA", "TestB", testingDir, goTestFileNameOne)
+
+		_, err := getGithubActionMatrixForTests(testingDir, "TestThatDoesntExist", "TestFeeMiddlewareTestSuite", nil)
+		assert.Error(t, err)
+	})
+
 	t.Run("non test files are not picked up", func(t *testing.T) {
 		testingDir := t.TempDir()
 		createFileWithTestSuiteAndTests(t, "FeeMiddlewareTestSuite", "TestA", "TestB", testingDir, nonTestFile)
 
-		gh, err := getGithubActionMatrixForTests(testingDir, "", nil)
+		gh, err := getGithubActionMatrixForTests(testingDir, "", "", nil)
 		assert.NoError(t, err)
 		assert.Empty(t, gh.Include)
 	})
@@ -105,7 +133,7 @@ type FeeMiddlewareTestSuite struct {}
 		err := os.WriteFile(path.Join(testingDir, goTestFileNameOne), []byte(fileWithTwoSuites), os.FileMode(0o777))
 		assert.NoError(t, err)
 
-		_, err = getGithubActionMatrixForTests(testingDir, "", nil)
+		_, err = getGithubActionMatrixForTests(testingDir, "", "", nil)
 		assert.Error(t, err)
 	})
 }