terraform test: Fill computed values of Nested collection type

.changes/v1.15/ENHANCEMENTS-20260223-130341.yaml

@@ -0,0 +1,5 @@
+kind: ENHANCEMENTS
+body: "mocking: computed values are now correctly filled for nested list, set, and map attributes when using mock and override data in tests."
+time: 2026-02-23T13:03:41.913383+01:00
+custom:
+  Issue: "37939"

internal/command/test_test.go

@@ -292,7 +292,7 @@ func TestTest_Runs(t *testing.T) {
 			code:        0,
 		},
 		"mocking": {
-			expectedOut: []string{"10 passed, 0 failed."},
+			expectedOut: []string{"11 passed, 0 failed."},
 			code:        0,
 		},
 		"mocking-invalid": {
@@ -377,12 +377,14 @@ func TestTest_Runs(t *testing.T) {
 			code:        0,
 		},
 		"write-only-attributes-mocked": {
-			expectedOut: []string{"1 passed, 0 failed."},
-			code:        0,
+			expectedOut: []string{"0 passed, 1 failed."},
+			expectedErr: []string{"Test assertion failed", "wrong value"},
+			code:        1,
 		},
 		"write-only-attributes-overridden": {
-			expectedOut: []string{"1 passed, 0 failed."},
-			code:        0,
+			expectedOut: []string{"0 passed, 1 failed."},
+			expectedErr: []string{"Test assertion failed", "wrong value"},
+			code:        1,
 		},
 		"with-default-variables": {
 			args:        []string{"-var=input_two=universe"},
@@ -5674,6 +5676,118 @@ func TestTest_TeardownOrder(t *testing.T) {
 	}
 }
 
+func TestTest_OverrideDataMocking(t *testing.T) {
+	tcs := map[string]struct {
+		dir            string
+		expectedCode   int
+		expectedStdout string
+		expectedStderr string
+	}{
+		"plain_list_attribute": {
+			dir:            "override_data_list_attribute",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+		"nested_list_attribute": {
+			dir:            "override_data_nested_list_attribute",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+		"nested_list_attribute_with_object_value": {
+			dir:            "override_data_nested_list_attribute_object",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+		"nested_list_attribute_with_invalid_type_value": {
+			dir:            "override_data_nested_list_attribute_invalid_type",
+			expectedCode:   1,
+			expectedStderr: "incompatible types; expected list of object, found",
+		},
+		"list_attribute_with_partial_element_values": {
+			dir:            "override_data_list_attribute_partial_elements",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+		"set_attribute_with_partial_element_values": {
+			dir:            "override_data_complex_set_attribute_partial_elements",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+		"nested_set_attribute_with_object_value": {
+			dir:            "override_data_complex_nested_set_attribute_object",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+		"nested_list_attribute_with_partial_element_values": {
+			dir:            "override_data_nested_list_attribute_partial_elements",
+			expectedCode:   0,
+			expectedStdout: "1 passed, 0 failed.",
+		},
+	}
+
+	for name, tc := range tcs {
+		t.Run(name, func(t *testing.T) {
+			td := t.TempDir()
+			testCopyDir(t, testFixturePath(path.Join("test", tc.dir)), td)
+			t.Chdir(td)
+
+			provider := testing_command.NewProvider(nil)
+			providerSource, closeFn := newMockProviderSource(t, map[string][]string{
+				"test": {"1.0.0"},
+			})
+			defer closeFn()
+
+			streams, done := terminal.StreamsForTesting(t)
+			view := views.NewView(streams)
+			ui := new(cli.MockUi)
+
+			meta := Meta{
+				testingOverrides: metaOverridesForProvider(provider.Provider),
+				Ui:               ui,
+				View:             view,
+				Streams:          streams,
+				ProviderSource:   providerSource,
+			}
+
+			init := &InitCommand{
+				Meta: meta,
+			}
+
+			if code := init.Run(nil); code != 0 {
+				output := done(t)
+				t.Fatalf("expected init status code 0 but got %d: %s", code, output.All())
+			}
+
+			streams, done = terminal.StreamsForTesting(t)
+			meta.Streams = streams
+			meta.View = views.NewView(streams)
+
+			c := &TestCommand{
+				Meta: meta,
+			}
+
+			code := c.Run([]string{"-no-color"})
+			output := done(t)
+
+			if code != tc.expectedCode {
+				t.Fatalf("expected status code %d but got %d:\n\n%s", tc.expectedCode, code, output.All())
+			}
+
+			if tc.expectedStdout != "" && !strings.Contains(output.Stdout(), tc.expectedStdout) {
+				t.Errorf("expected stdout to contain %q but got:\n\nstdout:\n%s\nstderr:\n%s", tc.expectedStdout, output.Stdout(), output.Stderr())
+			}
+
+			if tc.expectedStderr != "" && !strings.Contains(output.Stderr(), tc.expectedStderr) {
+				t.Errorf("expected stderr to contain %q but got:\n\nstdout:\n%s\nstderr:\n%s", tc.expectedStderr, output.Stdout(), output.Stderr())
+			}
+
+			if tc.expectedCode == 0 && output.Stderr() != "" {
+				t.Errorf("unexpected stderr output:\n%s", output.Stderr())
+			}
+		})
+	}
+}
+
 // testModuleInline takes a map of path -> config strings and yields a config
 // structure with those files loaded from disk
 func testModuleInline(t *testing.T, sources map[string]string) (*configs.Config, string, func()) {

internal/command/testdata/test/mocking/main.tf

@@ -24,12 +24,17 @@ variable "child_instances" {
 
 resource "test_resource" "primary" {
   provider = test.primary
-  count = var.instances
+  count    = var.instances
+}
+
+resource "test_complex_resource" "primary" {
+  provider = test.primary
+  count    = var.instances
 }
 
 resource "test_resource" "secondary" {
   provider = test.secondary
-  count = var.instances
+  count    = var.instances
 }
 
 module "child" {
@@ -38,7 +43,7 @@ module "child" {
   source = "./child"
 
   providers = {
-    test.primary = test.primary
+    test.primary   = test.primary
     test.secondary = test.secondary
   }
 

internal/command/testdata/test/mocking/tests/nested_mocked.tftest.hcl

@@ -0,0 +1,63 @@
+mock_provider "test" {
+  alias = "primary"
+
+  mock_resource "test_complex_resource" {
+    defaults = {
+      id = "aaaa"
+      list_value = [{name  = "first"}, {name  = "second"}]
+      nested_list_value = [{name  = "first"}, {name  = "second"}]
+      set_value = [{name  = "first"}, {name  = "second"}]
+      nested_set_value = [{name  = "first"}, {name  = "second"}]
+      map_value = tomap({
+        "key1": {
+          name  = "first"
+        },
+        "key2": {
+          name  = "third"
+        }
+      })
+      nested_map_value = tomap({
+        "key1": {
+          name  = "first"
+        },
+        "key2": {
+          name  = "third"
+        }
+      })
+    }
+  }
+}
+
+variables {
+  instances = 1
+  child_instances = 0
+}
+
+
+run "test" {
+
+  assert {
+    condition = test_complex_resource.primary[0].id == "aaaa"
+    error_message = "did not apply mocks"
+  }
+
+  assert {
+    condition = test_complex_resource.primary[0].list_value[0].name == "first"
+    error_message = "did not apply mocks"
+  }
+
+  assert {
+    condition = test_complex_resource.primary[0].nested_list_value[0].name == "first"
+    error_message = "did not apply mocks"
+  }
+
+  assert {
+    condition = test_complex_resource.primary[0].map_value["key1"].name == "first"
+    error_message = "did not apply mocks"
+  }
+
+  assert {
+    condition = test_complex_resource.primary[0].nested_map_value["key1"].name == "first"
+    error_message = "did not apply mocks"
+  }
+}

internal/command/testdata/test/override_data_attribute/list.tftest.hcl

@@ -0,0 +1,31 @@
+provider "test" {}
+
+override_data {
+  target = data.test_complex_data_source.datasource
+  values = {
+    list_value = [
+      {
+        name  = "first"
+        value = "one"
+      },
+      {
+        name  = "second"
+        value = "two"
+      },
+    ]
+  }
+}
+
+run "test_override_data_list_attribute" {
+  command = plan
+
+  assert {
+    condition     = length(data.test_complex_data_source.datasource.list_value) == 2
+    error_message = "Expected list_value to have 2 elements, got ${length(data.test_complex_data_source.datasource.list_value)}"
+  }
+
+  assert {
+    condition     = data.test_complex_data_source.datasource.list_value[0].name == "first"
+    error_message = "Expected first element name to be 'first'"
+  }
+}

internal/command/testdata/test/override_data_attribute/main.tf

@@ -0,0 +1,15 @@
+terraform {
+  required_providers {
+    test = {
+      source = "hashicorp/test"
+    }
+  }
+}
+
+data "test_complex_data_source" "datasource" {
+  id = "resource"
+}
+
+output "set_value" {
+  value = data.test_complex_data_source.datasource.set_value
+}

internal/command/testdata/test/override_data_attribute/map.tftest.hcl

@@ -0,0 +1,31 @@
+provider "test" {}
+
+override_data {
+  target = data.test_complex_data_source.datasource
+  values = {
+    map_value = {
+      "key1" = {
+        name  = "first"
+        value = "one"
+      }
+      "key2" = {
+        name  = "second"
+        value = "two"
+      }
+    }
+  }
+}
+
+run "test_override_data_map_attribute" {
+  command = plan
+
+  assert {
+    condition     = length(data.test_complex_data_source.datasource.map_value) == 2
+    error_message = "Expected map_value to have 2 elements, got ${length(data.test_complex_data_source.datasource.map_value)}"
+  }
+
+  assert {
+    condition     = data.test_complex_data_source.datasource.map_value["key1"].name == "first"
+    error_message = "Expected key1 name to be 'first'"
+  }
+}

internal/command/testdata/test/override_data_attribute/nested_list.tftest.hcl

@@ -0,0 +1,31 @@
+provider "test" {}
+
+override_data {
+  target = data.test_complex_data_source.datasource
+  values = {
+    nested_list_value = [
+      {
+        name  = "first"
+        value = "one"
+      },
+      {
+        name  = "second"
+        value = "two"
+      },
+    ]
+  }
+}
+
+run "test_override_data_nested_list_attribute" {
+  command = plan
+
+  assert {
+    condition     = length(data.test_complex_data_source.datasource.nested_list_value) == 2
+    error_message = "Expected nested_list_value to have 2 elements, got ${length(data.test_complex_data_source.datasource.nested_list_value)}"
+  }
+
+  assert {
+    condition     = data.test_complex_data_source.datasource.nested_list_value[0].name == "first"
+    error_message = "Expected first element name to be 'first'"
+  }
+}

internal/command/testdata/test/override_data_attribute/nested_map.tftest.hcl

@@ -0,0 +1,32 @@
+provider "test" {}
+
+override_data {
+  target = data.test_complex_data_source.datasource
+  values = {
+    nested_map_value = {
+      "key1" = {
+        name  = "first"
+        value = "one"
+      }
+      "key2" = {
+        name  = "second"
+        value = "two"
+      }
+    }
+  }
+}
+
+run "test_override_data_nested_map_attribute" {
+  command = plan
+
+  assert {
+    condition     = length(data.test_complex_data_source.datasource.nested_map_value) == 2
+    error_message = "Expected nested_map_value to have 2 elements, got ${length(data.test_complex_data_source.datasource.nested_map_value)}"
+  }
+
+  assert {
+    condition     = data.test_complex_data_source.datasource.nested_map_value["key1"].name == "first"
+    error_message = "Expected key1 name to be 'first'"
+  }
+
+}