Read extension metadata safely

internal/resources/extension/read.go

@@ -0,0 +1,76 @@
+package extension
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/terraform-plugin-framework/diag"
+	"github.com/hashicorp/terraform-plugin-framework/path"
+	kernel "github.com/kernel/kernel-go-sdk"
+	"github.com/kernel/terraform-provider-kernel/internal/projectscope"
+)
+
+type extensionReader interface {
+	GetExtension(context.Context, string, string) (*kernel.ExtensionGetResponse, error)
+}
+
+func readExtension(ctx context.Context, client extensionReader, state extensionModel) (extensionModel, bool, diag.Diagnostics) {
+	var diags diag.Diagnostics
+	if client == nil {
+		diags.AddError(
+			"Missing Kernel Client",
+			"The Kernel provider was not configured before using the extension resource.",
+		)
+		return extensionModel{}, false, diags
+	}
+
+	id, ok := extensionStateID(state, "read", &diags)
+	if !ok {
+		return extensionModel{}, false, diags
+	}
+	if state.ProjectID.IsUnknown() {
+		diags.AddAttributeError(
+			path.Root("project_id"),
+			"Unknown Kernel Project ID",
+			"Cannot read a Kernel extension while project_id is unknown in Terraform state.",
+		)
+		return extensionModel{}, false, diags
+	}
+
+	projectID := state.ProjectID.ValueString()
+	scope := "the API-key-bound project"
+	if projectID != "" {
+		scope = fmt.Sprintf("project %q", projectID)
+	}
+	response, err := client.GetExtension(ctx, projectID, id)
+	if err != nil {
+		if projectscope.IsNotFound(err) {
+			return extensionModel{}, true, diags
+		}
+		projectscope.AddError(&diags, "Read Kernel Extension", projectID, fmt.Errorf("read extension %q in %s: %w", id, scope, err))
+		return extensionModel{}, false, diags
+	}
+	if response == nil {
+		diags.AddError(
+			"Read Kernel Extension",
+			fmt.Sprintf("Kernel returned an empty response for extension %q in %s.", id, scope),
+		)
+		return extensionModel{}, false, diags
+	}
+
+	nextState, flattenDiags := flattenExtensionRead(*response, state)
+	diags.Append(flattenDiags...)
+	return nextState, false, diags
+}
+
+func extensionStateID(state extensionModel, operation string, diags *diag.Diagnostics) (string, bool) {
+	if state.ID.IsNull() || state.ID.IsUnknown() || state.ID.ValueString() == "" {
+		diags.AddAttributeError(
+			path.Root("id"),
+			"Missing Kernel Extension ID",
+			"Cannot "+operation+" a Kernel extension without a known id in Terraform state.",
+		)
+		return "", false
+	}
+	return state.ID.ValueString(), true
+}

internal/resources/extension/read_test.go

@@ -0,0 +1,179 @@
+package extension
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	kernel "github.com/kernel/kernel-go-sdk"
+	"github.com/kernel/terraform-provider-kernel/internal/kernelclient"
+)
+
+var _ extensionReader = kernelclient.Clients{}
+
+type fakeExtensionReader struct {
+	get func(context.Context, string, string) (*kernel.ExtensionGetResponse, error)
+}
+
+func (f fakeExtensionReader) GetExtension(ctx context.Context, projectID, id string) (*kernel.ExtensionGetResponse, error) {
+	if f.get == nil {
+		return nil, errors.New("unexpected get")
+	}
+	return f.get(ctx, projectID, id)
+}
+
+func TestReadExtensionGetsAndFlattensDurableState(t *testing.T) {
+	t.Parallel()
+
+	checksum := strings.Repeat("a", 64)
+	prior := extensionModel{
+		ID:           types.StringValue("extension_123"),
+		ProjectID:    types.StringValue("project_123"),
+		SourceSHA256: types.StringValue(checksum),
+	}
+	var gotProjectID, gotID string
+	next, removed, diags := readExtension(context.Background(), fakeExtensionReader{
+		get: func(ctx context.Context, projectID, id string) (*kernel.ExtensionGetResponse, error) {
+			gotProjectID, gotID = projectID, id
+			response := extensionGetResponseForTest(t, `{"id":"extension_123","name":"Extension","checksum":"`+checksum+`"}`)
+			return &response, nil
+		},
+	}, prior)
+	if diags.HasError() {
+		t.Fatalf("unexpected diagnostics: %v", diags)
+	}
+	if removed {
+		t.Fatal("removed = true, want false")
+	}
+	if gotProjectID != "project_123" || gotID != "extension_123" {
+		t.Fatalf("GetExtension scope/id = %q/%q, want project_123/extension_123", gotProjectID, gotID)
+	}
+	if got, want := next.Name.ValueString(), "Extension"; got != want {
+		t.Fatalf("name = %q, want %q", got, want)
+	}
+	if !next.ProjectID.Equal(prior.ProjectID) {
+		t.Fatalf("project_id = %v, want %v", next.ProjectID, prior.ProjectID)
+	}
+}
+
+func TestReadExtensionRemovesOnlyCodedNotFound(t *testing.T) {
+	t.Parallel()
+
+	tests := map[string]struct {
+		projectID   types.String
+		err         error
+		wantRemoved bool
+		wantSummary string
+		wantDetail  string
+	}{
+		"extension not found": {
+			err:         extensionAPIErrorForTest(t, http.StatusNotFound, `{"code":"not_found"}`),
+			wantRemoved: true,
+		},
+		"project not found": {
+			projectID:   types.StringValue("project_123"),
+			err:         extensionAPIErrorForTest(t, http.StatusNotFound, `{"code":"project_not_found"}`),
+			wantSummary: "Kernel Project Not Found",
+			wantDetail:  `extension_123`,
+		},
+		"uncoded not found": {
+			err:         extensionAPIErrorForTest(t, http.StatusNotFound, `{}`),
+			wantSummary: "Read Kernel Extension",
+			wantDetail:  "the API-key-bound project",
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			_, removed, diags := readExtension(context.Background(), fakeExtensionReader{
+				get: func(ctx context.Context, projectID, id string) (*kernel.ExtensionGetResponse, error) {
+					return nil, test.err
+				},
+			}, extensionModel{ID: types.StringValue("extension_123"), ProjectID: test.projectID})
+			if removed != test.wantRemoved {
+				t.Fatalf("removed = %t, want %t", removed, test.wantRemoved)
+			}
+			if test.wantSummary == "" {
+				if diags.HasError() {
+					t.Fatalf("unexpected diagnostics: %v", diags)
+				}
+			} else if !extensionDiagnosticContains(diags, test.wantSummary, test.wantDetail) {
+				t.Fatalf("diagnostics = %v, want %q", diags, test.wantSummary)
+			}
+		})
+	}
+}
+
+func TestReadExtensionRejectsInvalidStateBeforeGet(t *testing.T) {
+	t.Parallel()
+
+	tests := map[string]extensionModel{
+		"missing id":      {ID: types.StringNull(), ProjectID: types.StringNull()},
+		"unknown id":      {ID: types.StringUnknown(), ProjectID: types.StringNull()},
+		"empty id":        {ID: types.StringValue(""), ProjectID: types.StringNull()},
+		"unknown project": {ID: types.StringValue("extension_123"), ProjectID: types.StringUnknown()},
+	}
+
+	for name, state := range tests {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			called := false
+			_, removed, diags := readExtension(context.Background(), fakeExtensionReader{
+				get: func(ctx context.Context, projectID, id string) (*kernel.ExtensionGetResponse, error) {
+					called = true
+					return nil, nil
+				},
+			}, state)
+			if !diags.HasError() {
+				t.Fatal("expected invalid-state diagnostic")
+			}
+			if removed {
+				t.Fatal("removed = true, want false")
+			}
+			if called {
+				t.Fatal("GetExtension called for invalid state")
+			}
+		})
+	}
+}
+
+func TestReadExtensionReportsMissingClientAndEmptyResponse(t *testing.T) {
+	t.Parallel()
+
+	state := extensionModel{ID: types.StringValue("extension_123"), ProjectID: types.StringNull()}
+	tests := map[string]struct {
+		client  extensionReader
+		summary string
+		detail  string
+	}{
+		"missing client": {
+			summary: "Missing Kernel Client",
+		},
+		"empty response": {
+			client: fakeExtensionReader{
+				get: func(ctx context.Context, projectID, id string) (*kernel.ExtensionGetResponse, error) {
+					return nil, nil
+				},
+			},
+			summary: "Read Kernel Extension",
+			detail:  `extension_123`,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			_, removed, diags := readExtension(context.Background(), test.client, state)
+			if removed {
+				t.Fatal("removed = true, want false")
+			}
+			if !extensionDiagnosticContains(diags, test.summary, test.detail) {
+				t.Fatalf("diagnostics = %v, want %q", diags, test.summary)
+			}
+		})
+	}
+}