Refactor SDKv2 non-set detailed diff tests

pkg/internal/tests/pulcheck/pulcheck.go

@@ -40,6 +40,8 @@ func propNeedsUpdate(prop *schema.Schema) bool {
 	return true
 }
 
+// resourceNeedsUpdate returns true if the TF SDK schema validation would consider the
+// resource to need an update method.
 func resourceNeedsUpdate(res *schema.Resource) bool {
 	// If any of the properties need an update, then the resource needs an update.
 	for _, s := range res.Schema {
@@ -53,6 +55,26 @@ func resourceNeedsUpdate(res *schema.Resource) bool {
 // This is an experimental API.
 func EnsureProviderValid(t T, tfp *schema.Provider) {
 	for _, r := range tfp.ResourcesMap {
+		if r.Schema["id"] == nil {
+			r.Schema["id"] = &schema.Schema{
+				Type:     schema.TypeString,
+				Computed: true,
+			}
+		}
+
+		// If the resource will be flagged as not needing an Update method by the TF SDK schema
+		// validation then add a no-op update_prop property that will instead force the resource
+		// to need an Update method.
+		// This is necessary to work around a bug in the TF SDK schema validation where some resources which
+		// do need an Update method will instead be flagged as not needing an Update method.
+		// See https://github.com/pulumi/pulumi-terraform-bridge/pull/2723#issuecomment-2541518646
+		if !resourceNeedsUpdate(r) {
+			r.Schema["update_prop"] = &schema.Schema{
+				Type:     schema.TypeString,
+				Optional: true,
+			}
+		}
+
 		if r.ReadContext == nil {
 			r.ReadContext = func(_ context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
 				return nil
@@ -75,7 +97,9 @@ func EnsureProviderValid(t T, tfp *schema.Provider) {
 			}
 		}
 
-		if resourceNeedsUpdate(r) && r.UpdateContext == nil {
+		// Because of the no-op update_prop property added above, all resources will now
+		// need an Update method.
+		if r.UpdateContext == nil {
 			r.UpdateContext = func(
 				ctx context.Context, rd *schema.ResourceData, i interface{},
 			) diag.Diagnostics {

pkg/tests/detailed_diff_list_test.go

@@ -0,0 +1,221 @@
+package tests
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	"github.com/hexops/autogold/v2"
+	"github.com/zclconf/go-cty/cty"
+
+	crosstests "github.com/pulumi/pulumi-terraform-bridge/v3/pkg/internal/tests/cross-tests"
+)
+
+func TestDetailedDiffList(t *testing.T) {
+	t.Parallel()
+
+	listAttrSchema := schema.Resource{
+		Schema: map[string]*schema.Schema{
+			"list_attr": {
+				Type:     schema.TypeList,
+				Optional: true,
+				Elem:     &schema.Schema{Type: schema.TypeString},
+			},
+		},
+	}
+
+	maxItemsOneAttrSchema := schema.Resource{
+		Schema: map[string]*schema.Schema{
+			"list_attr": {
+				Type:     schema.TypeList,
+				Optional: true,
+				MaxItems: 1,
+				Elem:     &schema.Schema{Type: schema.TypeString},
+			},
+		},
+	}
+
+	listBlockSchema := schema.Resource{
+		Schema: map[string]*schema.Schema{
+			"list_block": {
+				Type:     schema.TypeList,
+				Optional: true,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"prop": {
+							Type:     schema.TypeString,
+							Optional: true,
+						},
+					},
+				},
+			},
+		},
+	}
+
+	maxItemsOneBlockSchema := schema.Resource{
+		Schema: map[string]*schema.Schema{
+			"list_block": {
+				Type:     schema.TypeList,
+				Optional: true,
+				MaxItems: 1,
+				Elem: &schema.Resource{
+					Schema: map[string]*schema.Schema{
+						"nested_prop": {
+							Type:     schema.TypeString,
+							Optional: true,
+						},
+					},
+				},
+			},
+		},
+	}
+
+	attrList := func(arr *[]string) map[string]cty.Value {
+		if arr == nil {
+			return map[string]cty.Value{}
+		}
+
+		if len(*arr) == 0 {
+			return map[string]cty.Value{
+				"list_attr": cty.ListValEmpty(cty.String),
+			}
+		}
+
+		slice := make([]cty.Value, len(*arr))
+		for i, v := range *arr {
+			slice[i] = cty.StringVal(v)
+		}
+		return map[string]cty.Value{
+			"list_attr": cty.ListVal(slice),
+		}
+	}
+
+	blockList := func(arr *[]string) map[string]cty.Value {
+		if arr == nil {
+			return map[string]cty.Value{}
+		}
+
+		if len(*arr) == 0 {
+			return map[string]cty.Value{
+				"list_block": cty.ListValEmpty(cty.DynamicPseudoType),
+			}
+		}
+
+		slice := make([]cty.Value, len(*arr))
+		for i, v := range *arr {
+			slice[i] = cty.ObjectVal(map[string]cty.Value{"prop": cty.StringVal(v)})
+		}
+		return map[string]cty.Value{
+			"list_block": cty.ListVal(slice),
+		}
+	}
+
+	nestedBlockList := func(arr *[]string) map[string]cty.Value {
+		if arr == nil {
+			return map[string]cty.Value{}
+		}
+
+		if len(*arr) == 0 {
+			return map[string]cty.Value{
+				"list_block": cty.ListValEmpty(cty.DynamicPseudoType),
+			}
+		}
+
+		slice := make([]cty.Value, len(*arr))
+		for i, v := range *arr {
+			slice[i] = cty.ObjectVal(map[string]cty.Value{"nested_prop": cty.StringVal(v)})
+		}
+		return map[string]cty.Value{
+			"list_block": cty.ListVal(slice),
+		}
+	}
+
+	listPairs := []struct {
+		name       string
+		schema     schema.Resource
+		valueMaker func(*[]string) map[string]cty.Value
+	}{
+		{"list attribute", listAttrSchema, attrList},
+		{"list block", listBlockSchema, blockList},
+	}
+
+	maxItemsOnePairs := []struct {
+		name       string
+		schema     schema.Resource
+		valueMaker func(*[]string) map[string]cty.Value
+	}{
+		{"max items one attribute", maxItemsOneAttrSchema, attrList},
+		{"max items one block", maxItemsOneBlockSchema, nestedBlockList},
+	}
+
+	oneElementScenarios := []struct {
+		name         string
+		initialValue *[]string
+		changeValue  *[]string
+	}{
+		{"unchanged empty", nil, nil},
+		{"unchanged non-empty", ref([]string{"val1"}), ref([]string{"val1"})},
+		{"added non-empty", nil, ref([]string{"val1"})},
+		{"added empty", nil, ref([]string{})},
+		{"removed non-empty", ref([]string{"val1"}), nil},
+		{"removed empty", ref([]string{}), nil},
+		{"changed", ref([]string{"val1"}), ref([]string{"val2"})},
+	}
+
+	multiElementScenarios := []struct {
+		name         string
+		initialValue *[]string
+		changeValue  *[]string
+	}{
+		{"list element added front", ref([]string{"val2", "val3"}), ref([]string{"val1", "val2", "val3"})},
+		{"list element added back", ref([]string{"val1", "val2"}), ref([]string{"val1", "val2", "val3"})},
+		{"list element added middle", ref([]string{"val1", "val3"}), ref([]string{"val1", "val2", "val3"})},
+		{"list element removed front", ref([]string{"val1", "val2", "val3"}), ref([]string{"val3", "val2"})},
+		{"list element removed middle", ref([]string{"val1", "val2", "val3"}), ref([]string{"val3", "val1"})},
+		{"list element removed end", ref([]string{"val1", "val2", "val3"}), ref([]string{"val2", "val1"})},
+	}
+
+	scenarios := append(oneElementScenarios, multiElementScenarios...)
+
+	type testOutput struct {
+		initialValue *[]string
+		changeValue  *[]string
+		tfOut        string
+		pulumiOut    string
+		detailedDiff map[string]any
+	}
+
+	runTest := func(t *testing.T, schema schema.Resource, valueMaker func(*[]string) map[string]cty.Value, initialValue *[]string, changeValue *[]string) {
+		diff := crosstests.Diff(t, &schema, valueMaker(initialValue), valueMaker(changeValue))
+		autogold.ExpectFile(t, testOutput{
+			initialValue: initialValue,
+			changeValue:  changeValue,
+			tfOut:        diff.TFOut,
+			pulumiOut:    diff.PulumiOut,
+			detailedDiff: diff.PulumiDiff.DetailedDiff,
+		})
+	}
+
+	for _, schemaValueMakerPair := range listPairs {
+		t.Run(schemaValueMakerPair.name, func(t *testing.T) {
+			t.Parallel()
+			for _, scenario := range scenarios {
+				t.Run(scenario.name, func(t *testing.T) {
+					t.Parallel()
+					runTest(t, schemaValueMakerPair.schema, schemaValueMakerPair.valueMaker, scenario.initialValue, scenario.changeValue)
+				})
+			}
+		})
+	}
+
+	for _, schemaValueMakerPair := range maxItemsOnePairs {
+		t.Run(schemaValueMakerPair.name, func(t *testing.T) {
+			t.Parallel()
+			for _, scenario := range oneElementScenarios {
+				t.Run(scenario.name, func(t *testing.T) {
+					t.Parallel()
+					runTest(t, schemaValueMakerPair.schema, schemaValueMakerPair.valueMaker, scenario.initialValue, scenario.changeValue)
+				})
+			}
+		})
+	}
+}