refactor: unify how executor tests are written (#2042)

* feat: use TaskTest for executor tests

* feat: more tests

* feat: separate tests for executing and formatting with new functional options that work for both test types

* feat: formatter tests

* refactor: more tests

formatter_test.go

@@ -0,0 +1,220 @@
+package task_test
+
+import (
+	"bytes"
+	"path/filepath"
+	"testing"
+
+	"github.com/sebdah/goldie/v2"
+	"github.com/stretchr/testify/require"
+
+	"github.com/go-task/task/v3"
+	"github.com/go-task/task/v3/internal/experiments"
+	"github.com/go-task/task/v3/taskfile/ast"
+)
+
+type (
+	// A FormatterTestOption is a function that configures an [FormatterTest].
+	FormatterTestOption interface {
+		applyToFormatterTest(*FormatterTest)
+	}
+	// A FormatterTest is a test wrapper around a [task.Executor] to make it
+	// easy to write tests for the task formatter. See [NewFormatterTest] for
+	// information on creating and running FormatterTests. These tests use
+	// fixture files to assert whether the result of the output is correct. If
+	// Task's behavior has been changed, the fixture files can be updated by
+	// running `task gen:fixtures`.
+	FormatterTest struct {
+		TaskTest
+		task           string
+		vars           map[string]any
+		executorOpts   []task.ExecutorOption
+		listOptions    task.ListOptions
+		wantSetupError bool
+		wantListError  bool
+	}
+)
+
+// NewFormatterTest sets up a new [task.Executor] with the given options and
+// runs a task with the given [FormatterTestOption]s. The output of the task is
+// written to a set of fixture files depending on the configuration of the test.
+func NewFormatterTest(t *testing.T, opts ...FormatterTestOption) {
+	t.Helper()
+	tt := &FormatterTest{
+		task: "default",
+		vars: map[string]any{},
+		TaskTest: TaskTest{
+			experiments: map[*experiments.Experiment]int{},
+		},
+	}
+	// Apply the functional options
+	for _, opt := range opts {
+		opt.applyToFormatterTest(tt)
+	}
+	// Enable any experiments that have been set
+	for x, v := range tt.experiments {
+		prev := *x
+		*x = experiments.Experiment{
+			Name:          prev.Name,
+			AllowedValues: []int{v},
+			Value:         v,
+		}
+		t.Cleanup(func() {
+			*x = prev
+		})
+	}
+	tt.run(t)
+}
+
+// Functional options
+
+// WithListOptions sets the list options for the formatter.
+func WithListOptions(opts task.ListOptions) FormatterTestOption {
+	return &listOptionsTestOption{opts}
+}
+
+type listOptionsTestOption struct {
+	listOptions task.ListOptions
+}
+
+func (opt *listOptionsTestOption) applyToFormatterTest(t *FormatterTest) {
+	t.listOptions = opt.listOptions
+}
+
+// WithListError tells the test to expect an error when running the formatter.
+// A fixture will be created with the output of any errors.
+func WithListError() FormatterTestOption {
+	return &listErrorTestOption{}
+}
+
+type listErrorTestOption struct{}
+
+func (opt *listErrorTestOption) applyToFormatterTest(t *FormatterTest) {
+	t.wantListError = true
+}
+
+// Helpers
+
+// writeFixtureErrList is a wrapper for writing the output of an error when
+// running the formatter to a fixture file.
+func (tt *FormatterTest) writeFixtureErrList(
+	t *testing.T,
+	g *goldie.Goldie,
+	err error,
+) {
+	t.Helper()
+	tt.writeFixture(t, g, "err-list", []byte(err.Error()))
+}
+
+// run is the main function for running the test. It sets up the task executor,
+// runs the task, and writes the output to a fixture file.
+func (tt *FormatterTest) run(t *testing.T) {
+	t.Helper()
+	f := func(t *testing.T) {
+		t.Helper()
+		var buf bytes.Buffer
+
+		opts := append(
+			tt.executorOpts,
+			task.ExecutorWithStdout(&buf),
+			task.ExecutorWithStderr(&buf),
+		)
+
+		// Set up the task executor
+		e := task.NewExecutor(opts...)
+
+		// Create a golden fixture file for the output
+		g := goldie.New(t,
+			goldie.WithFixtureDir(filepath.Join(e.Dir, "testdata")),
+		)
+
+		// Call setup and check for errors
+		if err := e.Setup(); tt.wantSetupError {
+			require.Error(t, err)
+			tt.writeFixtureErrSetup(t, g, err)
+			tt.writeFixtureBuffer(t, g, buf)
+			return
+		} else {
+			require.NoError(t, err)
+		}
+
+		// Create the task call
+		vars := ast.NewVars()
+		for key, value := range tt.vars {
+			vars.Set(key, ast.Var{Value: value})
+		}
+
+		// Run the formatter and check for errors
+		if _, err := e.ListTasks(tt.listOptions); tt.wantListError {
+			require.Error(t, err)
+			tt.writeFixtureErrList(t, g, err)
+			tt.writeFixtureBuffer(t, g, buf)
+			return
+		} else {
+			require.NoError(t, err)
+		}
+
+		tt.writeFixtureBuffer(t, g, buf)
+	}
+
+	// Run the test (with a name if it has one)
+	if tt.name != "" {
+		t.Run(tt.name, f)
+	} else {
+		f(t)
+	}
+}
+
+func TestNoLabelInList(t *testing.T) {
+	t.Parallel()
+
+	NewFormatterTest(t,
+		WithExecutorOptions(
+			task.ExecutorWithDir("testdata/label_list"),
+		),
+		WithListOptions(task.ListOptions{
+			ListOnlyTasksWithDescriptions: true,
+		}),
+	)
+}
+
+// task -al case 1: listAll list all tasks
+func TestListAllShowsNoDesc(t *testing.T) {
+	t.Parallel()
+
+	NewFormatterTest(t,
+		WithExecutorOptions(
+			task.ExecutorWithDir("testdata/list_mixed_desc"),
+		),
+		WithListOptions(task.ListOptions{
+			ListAllTasks: true,
+		}),
+	)
+}
+
+// task -al case 2: !listAll list some tasks (only those with desc)
+func TestListCanListDescOnly(t *testing.T) {
+	t.Parallel()
+
+	NewFormatterTest(t,
+		WithExecutorOptions(
+			task.ExecutorWithDir("testdata/list_mixed_desc"),
+		),
+		WithListOptions(task.ListOptions{
+			ListOnlyTasksWithDescriptions: true,
+		}),
+	)
+}
+
+func TestListDescInterpolation(t *testing.T) {
+	t.Parallel()
+
+	NewFormatterTest(t,
+		WithExecutorOptions(
+			task.ExecutorWithDir("testdata/list_desc_interpolation"),
+		),
+		WithListOptions(task.ListOptions{
+			ListOnlyTasksWithDescriptions: true,
+		}),
+	)
+}