fix(featuredetection): add ReleaseFeatures method

Signed-off-by: Babak K. Shandiz <babakks@github.com>

internal/featuredetection/detector_mock.go

@@ -24,6 +24,10 @@ func (md *DisabledDetectorMock) SearchFeatures() (SearchFeatures, error) {
 	return advancedIssueSearchNotSupported, nil
 }
 
+func (md *DisabledDetectorMock) ReleaseFeatures() (ReleaseFeatures, error) {
+	return ReleaseFeatures{}, nil
+}
+
 type EnabledDetectorMock struct{}
 
 func (md *EnabledDetectorMock) IssueFeatures() (IssueFeatures, error) {
@@ -46,6 +50,12 @@ func (md *EnabledDetectorMock) SearchFeatures() (SearchFeatures, error) {
 	return advancedIssueSearchNotSupported, nil
 }
 
+func (md *EnabledDetectorMock) ReleaseFeatures() (ReleaseFeatures, error) {
+	return ReleaseFeatures{
+		ImmutableReleases: true,
+	}, nil
+}
+
 type AdvancedIssueSearchDetectorMock struct {
 	EnabledDetectorMock
 	searchFeatures SearchFeatures

internal/featuredetection/feature_detection.go

@@ -17,6 +17,7 @@ type Detector interface {
 	RepositoryFeatures() (RepositoryFeatures, error)
 	ProjectsV1() gh.ProjectsV1Support
 	SearchFeatures() (SearchFeatures, error)
+	ReleaseFeatures() (ReleaseFeatures, error)
 }
 
 type IssueFeatures struct {
@@ -93,6 +94,10 @@ var advancedIssueSearchSupportedAsOnlyBackend = SearchFeatures{
 	AdvancedIssueSearchAPIOptIn: false,
 }
 
+type ReleaseFeatures struct {
+	ImmutableReleases bool
+}
+
 type detector struct {
 	host       string
 	httpClient *http.Client
@@ -358,6 +363,36 @@ func (d *detector) SearchFeatures() (SearchFeatures, error) {
 	return feature, nil
 }
 
+func (d *detector) ReleaseFeatures() (ReleaseFeatures, error) {
+	// TODO: immutableReleaseFullSupport
+	// Once all supported GHES versions fully support immutable releases, we can
+	// remove this function, of course, unless there will be other release-related
+	// features that are not available on all GH hosts.
+
+	var releaseFeatureDetection struct {
+		Release struct {
+			Fields []struct {
+				Name string
+			} `graphql:"fields"`
+		} `graphql:"Release: __type(name: \"Release\")"`
+	}
+
+	gql := api.NewClientFromHTTP(d.httpClient)
+	if err := gql.Query(d.host, "Release_fields", &releaseFeatureDetection, nil); err != nil {
+		return ReleaseFeatures{}, err
+	}
+
+	for _, field := range releaseFeatureDetection.Release.Fields {
+		if field.Name == "immutable" {
+			return ReleaseFeatures{
+				ImmutableReleases: true,
+			}, nil
+		}
+	}
+
+	return ReleaseFeatures{}, nil
+}
+
 func resolveEnterpriseVersion(httpClient *http.Client, host string) (*version.Version, error) {
 	var metaResponse struct {
 		InstalledVersion string `json:"installed_version"`

internal/featuredetection/feature_detection_test.go

@@ -585,3 +585,114 @@ func TestAdvancedIssueSearchSupport(t *testing.T) {
 		})
 	}
 }
+
+func TestReleaseFeatures(t *testing.T) {
+	withImmutableReleaseSupport := `{"data":{"Release":{"fields":[{"name":"author"},{"name":"name"},{"name":"immutable"}]}}}`
+	withoutImmutableReleaseSupport := `{"data":{"Release":{"fields":[{"name":"author"},{"name":"name"}]}}}`
+
+	tests := []struct {
+		name         string
+		hostname     string
+		httpStubs    func(*httpmock.Registry)
+		wantFeatures ReleaseFeatures
+	}{
+		{
+			// This is not a real case as `github.com` supports immutable releases.
+			name:     "github.com, immutable releases unsupported",
+			hostname: "github.com",
+			httpStubs: func(reg *httpmock.Registry) {
+				reg.Register(
+					httpmock.GraphQL(`query Release_fields\b`),
+					httpmock.StringResponse(withoutImmutableReleaseSupport),
+				)
+			},
+			wantFeatures: ReleaseFeatures{
+				ImmutableReleases: false,
+			},
+		},
+		{
+			name:     "github.com, immutable releases supported",
+			hostname: "github.com",
+			httpStubs: func(reg *httpmock.Registry) {
+				reg.Register(
+					httpmock.GraphQL(`query Release_fields\b`),
+					httpmock.StringResponse(withImmutableReleaseSupport),
+				)
+			},
+			wantFeatures: ReleaseFeatures{
+				ImmutableReleases: true,
+			},
+		},
+		{
+			// This is not a real case as `github.com` supports immutable releases.
+			name:     "ghec data residency (ghe.com), immutable releases unsupported",
+			hostname: "stampname.ghe.com",
+			httpStubs: func(reg *httpmock.Registry) {
+				reg.Register(
+					httpmock.GraphQL(`query Release_fields\b`),
+					httpmock.StringResponse(withoutImmutableReleaseSupport),
+				)
+			},
+			wantFeatures: ReleaseFeatures{
+				ImmutableReleases: false,
+			},
+		},
+		{
+			name:     "ghec data residency (ghe.com), immutable releases supported",
+			hostname: "stampname.ghe.com",
+			httpStubs: func(reg *httpmock.Registry) {
+				reg.Register(
+					httpmock.GraphQL(`query Release_fields\b`),
+					httpmock.StringResponse(withImmutableReleaseSupport),
+				)
+			},
+			wantFeatures: ReleaseFeatures{
+				ImmutableReleases: true,
+			},
+		},
+		{
+			name:     "GHE, immutable releases unsupported",
+			hostname: "git.my.org",
+			httpStubs: func(reg *httpmock.Registry) {
+				reg.Register(
+					httpmock.GraphQL(`query Release_fields\b`),
+					httpmock.StringResponse(withoutImmutableReleaseSupport),
+				)
+			},
+			wantFeatures: ReleaseFeatures{
+				ImmutableReleases: false,
+			},
+		},
+		{
+			name:     "GHE, immutable releases supported",
+			hostname: "git.my.org",
+			httpStubs: func(reg *httpmock.Registry) {
+				reg.Register(
+					httpmock.GraphQL(`query Release_fields\b`),
+					httpmock.StringResponse(withImmutableReleaseSupport),
+				)
+			},
+			wantFeatures: ReleaseFeatures{
+				ImmutableReleases: true,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			reg := &httpmock.Registry{}
+			if tt.httpStubs != nil {
+				tt.httpStubs(reg)
+			}
+			httpClient := &http.Client{}
+			httpmock.ReplaceTripper(httpClient, reg)
+
+			detector := NewDetector(httpClient, tt.hostname)
+
+			features, err := detector.ReleaseFeatures()
+			require.NoError(t, err)
+			require.Equal(t, tt.wantFeatures, features)
+		})
+	}
+}