feat: add a deprecation warning when running Taskfiles with a v2 schema

CHANGELOG.md

@@ -2,8 +2,10 @@
 
 ## Unreleased
 
-- Only rewrite checksum files in `.task` if the checksum has changed
-  (#1185, #1194 by @deviantintegral).
+- Only rewrite checksum files in `.task` if the checksum has changed (#1185,
+  #1194 by @deviantintegral).
+- Deprecated `version: 2` schema. This will be removed in the next major release
+  (#1197, #1198, #1199 by @pd93).
 
 ## v3.25.0 - 2023-05-22
 
@@ -16,7 +18,8 @@
 - Fix some errors being unintendedly supressed (#1134 by @clintmod).
 - Fix a nil pointer error when `version` is omitted from a Taskfile (#1148,
   #1149 by @pd93).
-- Fix duplicate error message when a task does not exists (#1141, #1144 by @pd93).
+- Fix duplicate error message when a task does not exists (#1141, #1144 by
+  @pd93).
 
 ## v3.24.0 - 2023-04-15
 

setup.go

@@ -250,7 +250,11 @@ func (e *Executor) doVersionChecks() error {
 	*v = *e.Taskfile.Version
 
 	if v.LessThan(taskfile.V2) {
-		return fmt.Errorf(`task: Taskfile versions prior to v2 are not supported anymore`)
+		return fmt.Errorf(`task: version 1 schemas are no longer supported`)
+	}
+
+	if v.LessThan(taskfile.V3) {
+		e.Logger.Errf(logger.Yellow, "task: version 2 schemas are deprecated and will be removed in a future release\nSee https://github.com/go-task/task/issues/1197 for more details\n")
 	}
 
 	// consider as equal to the greater version if round

task_test.go

@@ -1371,15 +1371,27 @@ func TestDynamicVariablesShouldRunOnTheTaskDir(t *testing.T) {
 	tt.Run(t)
 }
 
-func TestDisplaysErrorOnUnsupportedVersion(t *testing.T) {
+func TestDisplaysErrorOnVersion1Schema(t *testing.T) {
 	e := task.Executor{
 		Dir:    "testdata/version/v1",
 		Stdout: io.Discard,
 		Stderr: io.Discard,
 	}
 	err := e.Setup()
 	require.Error(t, err)
-	assert.Equal(t, "task: Taskfile versions prior to v2 are not supported anymore", err.Error())
+	assert.Equal(t, "task: version 1 schemas are no longer supported", err.Error())
+}
+
+func TestDisplaysWarningOnVersion2Schema(t *testing.T) {
+	var buff bytes.Buffer
+	e := task.Executor{
+		Dir:    "testdata/version/v2",
+		Stdout: io.Discard,
+		Stderr: &buff,
+	}
+	err := e.Setup()
+	require.NoError(t, err)
+	assert.Equal(t, "task: version 2 schemas are deprecated and will be removed in a future release\nSee https://github.com/go-task/task/issues/1197 for more details\n", buff.String())
 }
 
 func TestShortTaskNotation(t *testing.T) {