Change analysis server protocol to omit empty lists when optional.

pkg/analysis_server/test/integration/integration_test_methods.dart

Index: pkg/analysis_server/test/integration/integration_test_methods.dart
diff --git a/pkg/analysis_server/test/integration/integration_test_methods.dart b/pkg/analysis_server/test/integration/integration_test_methods.dart
index 0e13d4b4fa926b2d76d4a39dc04fb25c44032202..9c1392865259d6ee9062600210db6abe3c7698f6 100644
--- a/pkg/analysis_server/test/integration/integration_test_methods.dart
+++ b/pkg/analysis_server/test/integration/integration_test_methods.dart
@@ -71,13 +71,15 @@ abstract class IntegrationTestMixin {
    *
    * Parameters
    *
-   * subscriptions ( List<ServerService> )
+   * subscriptions ( optional List<ServerService> )
    *
    *   A list of the services being subscribed to.
    */
-  Future sendServerSetSubscriptions(List<String> subscriptions, {bool checkTypes: true}) {
+  Future sendServerSetSubscriptions({List<String> subscriptions, bool checkTypes: true}) {
     Map<String, dynamic> params = {};
-    params["subscriptions"] = subscriptions;
+    if (subscriptions != null) {
+      params["subscriptions"] = subscriptions;
+    }
     if (checkTypes) {
       expect(params, isServerSetSubscriptionsParams);
     }
@@ -180,7 +182,7 @@ abstract class IntegrationTestMixin {
    *
    * Returns
    *
-   * errors ( List<AnalysisError> )
+   * errors ( optional List<AnalysisError> )
    *
    *   The errors associated with the file.
    */
@@ -216,10 +218,10 @@ abstract class IntegrationTestMixin {
    *
    * Returns
    *
-   * hovers ( List<HoverInformation> )
+   * hovers ( optional List<HoverInformation> )
    *
    *   The hover information associated with the location. The list will be
-   *   empty if no information could be determined for the location. The list
+   *   omitted if no information could be determined for the location. The list
    *   can contain multiple items if the file is being analyzed in multiple
    *   contexts in conflicting ways (such as a part that is included in
    *   multiple libraries).
@@ -280,19 +282,23 @@ abstract class IntegrationTestMixin {
    *
    * Parameters
    *
-   * included ( List<FilePath> )
+   * included ( optional List<FilePath> )
    *
    *   A list of the files and directories that should be analyzed.
    *
-   * excluded ( List<FilePath> )
+   * excluded ( optional List<FilePath> )
    *
    *   A list of the files and directories within the included directories that
    *   should not be analyzed.
    */
-  Future sendAnalysisSetAnalysisRoots(List<String> included, List<String> excluded, {bool checkTypes: true}) {
+  Future sendAnalysisSetAnalysisRoots({List<String> included, List<String> excluded, bool checkTypes: true}) {
     Map<String, dynamic> params = {};
-    params["included"] = included;
-    params["excluded"] = excluded;
+    if (included != null) {
+      params["included"] = included;
+    }
+    if (excluded != null) {
+      params["excluded"] = excluded;
+    }
     if (checkTypes) {
       expect(params, isAnalysisSetAnalysisRootsParams);
     }
@@ -326,13 +332,15 @@ abstract class IntegrationTestMixin {
    *
    * Parameters
    *
-   * files ( List<FilePath> )
+   * files ( optional List<FilePath> )
    *
    *   The files that are to be a priority for analysis.
    */
-  Future sendAnalysisSetPriorityFiles(List<String> files, {bool checkTypes: true}) {
+  Future sendAnalysisSetPriorityFiles({List<String> files, bool checkTypes: true}) {
     Map<String, dynamic> params = {};
-    params["files"] = files;
+    if (files != null) {
+      params["files"] = files;
+    }
     if (checkTypes) {
       expect(params, isAnalysisSetPriorityFilesParams);
     }
@@ -464,7 +472,7 @@ abstract class IntegrationTestMixin {
    *
    *   The file containing the errors.
    *
-   * errors ( List<AnalysisError> )
+   * errors ( optional List<AnalysisError> )
    *
    *   The errors contained in the file.
    */
@@ -490,7 +498,7 @@ abstract class IntegrationTestMixin {
    *
    * Parameters
    *
-   * files ( List<FilePath> )
+   * files ( optional List<FilePath> )
    *
    *   The files that are no longer being analyzed.
    */
@@ -517,7 +525,7 @@ abstract class IntegrationTestMixin {
    *
    *   The file containing the folding regions.
    *
-   * regions ( List<FoldingRegion> )
+   * regions ( optional List<FoldingRegion> )
    *
    *   The folding regions contained in the file.
    */
@@ -541,7 +549,7 @@ abstract class IntegrationTestMixin {
    *
    *   The file containing the highlight regions.
    *
-   * regions ( List<HighlightRegion> )
+   * regions ( optional List<HighlightRegion> )
    *
    *   The highlight regions contained in the file. Each highlight region
    *   represents a particular syntactic or semantic meaning associated with
@@ -569,7 +577,7 @@ abstract class IntegrationTestMixin {
    *
    *   The file containing the navigation regions.
    *
-   * regions ( List<NavigationRegion> )
+   * regions ( optional List<NavigationRegion> )
    *
    *   The navigation regions contained in the file. Each navigation region
    *   represents a list of targets associated with some range. The lists will
@@ -599,7 +607,7 @@ abstract class IntegrationTestMixin {
    *
    *   The file in which the references occur.
    *
-   * occurrences ( List<Occurrences> )
+   * occurrences ( optional List<Occurrences> )
    *
    *   The occurrences of references to elements within the file.
    */
@@ -647,7 +655,7 @@ abstract class IntegrationTestMixin {
    *
    *   The file with which the overrides are associated.
    *
-   * overrides ( List<Override> )
+   * overrides ( optional List<Override> )
    *
    *   The overrides associated with the file.
    */
@@ -719,7 +727,7 @@ abstract class IntegrationTestMixin {
    *   containing the cursor is to be replaced when the suggestion is applied
    *   (that is, the number of characters in the existing identifier).
    *
-   * results ( List<CompletionSuggestion> )
+   * results ( optional List<CompletionSuggestion> )
    *
    *   The completion suggestions being reported. The notification contains all
    *   possible completions at the requested cursor position, even those that
@@ -956,7 +964,7 @@ abstract class IntegrationTestMixin {
    *
    *   The id associated with the search.
    *
-   * results ( List<SearchResult> )
+   * results ( optional List<SearchResult> )
    *
    *   The search results being reported.
    *
@@ -994,7 +1002,7 @@ abstract class IntegrationTestMixin {
    *
    * Returns
    *
-   * assists ( List<SourceChange> )
+   * assists ( optional List<SourceChange> )
    *
    *   The assists that are available at the given location.
    */
@@ -1035,7 +1043,7 @@ abstract class IntegrationTestMixin {
    *
    * Returns
    *
-   * kinds ( List<RefactoringKind> )
+   * kinds ( optional List<RefactoringKind> )
    *
    *   The kinds of refactorings that are valid for the given selection.
    */
@@ -1072,7 +1080,7 @@ abstract class IntegrationTestMixin {
    *
    * Returns
    *
-   * fixes ( List<ErrorFixes> )
+   * fixes ( optional List<ErrorFixes> )
    *
    *   The fixes that are available for each of the analysis errors. There is a
    *   one-to-one correspondence between the analysis errors in the request and
@@ -1133,7 +1141,7 @@ abstract class IntegrationTestMixin {
    *
    * Returns
    *
-   * status ( List<RefactoringProblem> )
+   * status ( optional List<RefactoringProblem> )
    *
    *   The status of the refactoring. The array will be empty if there are no
    *   known problems.
@@ -1307,13 +1315,15 @@ abstract class IntegrationTestMixin {
    *
    * Parameters
    *
-   * subscriptions ( List<DebugService> )
+   * subscriptions ( optional List<DebugService> )
    *
    *   A list of the services being subscribed to.
    */
-  Future sendDebugSetSubscriptions(List<String> subscriptions, {bool checkTypes: true}) {
+  Future sendDebugSetSubscriptions({List<String> subscriptions, bool checkTypes: true}) {
     Map<String, dynamic> params = {};
-    params["subscriptions"] = subscriptions;
+    if (subscriptions != null) {
+      params["subscriptions"] = subscriptions;
+    }
     if (checkTypes) {
       expect(params, isDebugSetSubscriptionsParams);
     }
@@ -1336,7 +1346,7 @@ abstract class IntegrationTestMixin {
    *
    * Parameters
    *
-   * executables ( List<ExecutableFile> )
+   * executables ( optional List<ExecutableFile> )
    *
    *   A list of the files that are executable in the given context. This list
    *   replaces any previous list provided for the given context.