chore: modify parameter dynamic immutability behavior (#18583)

Immutability behavior is determined by the current build, not affected by the previous

enterprise/coderd/dynamicparameters_test.go

@@ -338,7 +338,6 @@ func TestDynamicParameterBuild(t *testing.T) {
 			bld, err := templateAdmin.CreateWorkspaceBuild(ctx, wrk.ID, codersdk.CreateWorkspaceBuildRequest{
 				TemplateVersionID: immutable.ID, // Use the new template version with the immutable parameter
 				Transition:        codersdk.WorkspaceTransitionDelete,
-				DryRun:            false,
 			})
 			require.NoError(t, err)
 			coderdtest.AwaitWorkspaceBuildJobCompleted(t, templateAdmin, bld.ID)
@@ -354,6 +353,75 @@ func TestDynamicParameterBuild(t *testing.T) {
 			require.NoError(t, err)
 			require.Equal(t, wrk.ID, deleted.ID, "workspace should be deleted")
 		})
+
+		t.Run("PreviouslyImmutable", func(t *testing.T) {
+			// Ok this is a weird test to document how things are working.
+			// What if a parameter flips it's immutability based on a value?
+			// The current behavior is to source immutability from the new state.
+			// So the value is allowed to be changed.
+			t.Parallel()
+
+			ctx := testutil.Context(t, testutil.WaitShort)
+			// Start with a new template that has 1 parameter that is immutable
+			immutable, _ := coderdtest.DynamicParameterTemplate(t, templateAdmin, orgID, coderdtest.DynamicParameterTemplateParams{
+				MainTF: "# PreviouslyImmutable\n" + string(must(os.ReadFile("testdata/parameters/dynamicimmutable/main.tf"))),
+			})
+
+			// Create the workspace with the immutable parameter
+			wrk, err := templateAdmin.CreateUserWorkspace(ctx, codersdk.Me, codersdk.CreateWorkspaceRequest{
+				TemplateID: immutable.ID,
+				Name:       coderdtest.RandomUsername(t),
+				RichParameterValues: []codersdk.WorkspaceBuildParameter{
+					{Name: "isimmutable", Value: "true"},
+					{Name: "immutable", Value: "coder"},
+				},
+			})
+			require.NoError(t, err)
+			coderdtest.AwaitWorkspaceBuildJobCompleted(t, templateAdmin, wrk.LatestBuild.ID)
+
+			// Try new values
+			_, err = templateAdmin.CreateWorkspaceBuild(ctx, wrk.ID, codersdk.CreateWorkspaceBuildRequest{
+				Transition: codersdk.WorkspaceTransitionStart,
+				RichParameterValues: []codersdk.WorkspaceBuildParameter{
+					{Name: "isimmutable", Value: "false"},
+					{Name: "immutable", Value: "not-coder"},
+				},
+			})
+			require.NoError(t, err)
+		})
+
+		t.Run("PreviouslyMutable", func(t *testing.T) {
+			// The value cannot be changed because it becomes immutable.
+			t.Parallel()
+
+			ctx := testutil.Context(t, testutil.WaitShort)
+			immutable, _ := coderdtest.DynamicParameterTemplate(t, templateAdmin, orgID, coderdtest.DynamicParameterTemplateParams{
+				MainTF: "# PreviouslyMutable\n" + string(must(os.ReadFile("testdata/parameters/dynamicimmutable/main.tf"))),
+			})
+
+			// Create the workspace with the mutable parameter
+			wrk, err := templateAdmin.CreateUserWorkspace(ctx, codersdk.Me, codersdk.CreateWorkspaceRequest{
+				TemplateID: immutable.ID,
+				Name:       coderdtest.RandomUsername(t),
+				RichParameterValues: []codersdk.WorkspaceBuildParameter{
+					{Name: "isimmutable", Value: "false"},
+					{Name: "immutable", Value: "coder"},
+				},
+			})
+			require.NoError(t, err)
+			coderdtest.AwaitWorkspaceBuildJobCompleted(t, templateAdmin, wrk.LatestBuild.ID)
+
+			// Switch it to immutable, which breaks the validation
+			_, err = templateAdmin.CreateWorkspaceBuild(ctx, wrk.ID, codersdk.CreateWorkspaceBuildRequest{
+				Transition: codersdk.WorkspaceTransitionStart,
+				RichParameterValues: []codersdk.WorkspaceBuildParameter{
+					{Name: "isimmutable", Value: "true"},
+					{Name: "immutable", Value: "not-coder"},
+				},
+			})
+			require.Error(t, err)
+			require.ErrorContains(t, err, "is not mutable")
+		})
 	})
 }
 

enterprise/coderd/testdata/parameters/dynamicimmutable/main.tf

@@ -0,0 +1,23 @@
+terraform {
+  required_providers {
+    coder = {
+      source = "coder/coder"
+    }
+  }
+}
+
+data "coder_workspace_owner" "me" {}
+
+data "coder_parameter" "isimmutable" {
+  name    = "isimmutable"
+  type    = "bool"
+  mutable = true
+  default = "true"
+}
+
+data "coder_parameter" "immutable" {
+  name    = "immutable"
+  type    = "string"
+  mutable = data.coder_parameter.isimmutable.value == "false"
+  default = "Hello World"
+}