Test tags from suites should be inherited (#1015)

Tags defined on swift-testing suites are meant to be inherited by child
suites/tests. VS Code doesn't apply this inheritance automatically, so
we must set a suite's tags on its children ourselves.

Issue: #1014

Author: plemarquand

src/TestExplorer/TestDiscovery.ts

@@ -158,6 +158,27 @@ function deepMergeTestItemChildren(existingItem: vscode.TestItem, newItem: vscod
     );
 }
 
+/**
+ * Given a `TestClass` adds the TestClasses tags to each of its children.
+ * Does not apply recursively.
+ * @param testClass A test class whose tags should be propagated to its children.
+ * @returns A `TestClass` whose children include the parent's tags.
+ */
+function applyTagsToChildren(testClass: TestClass): TestClass {
+    return {
+        ...testClass,
+        children: testClass.children.reduce((children, child) => {
+            return [
+                ...children,
+                {
+                    ...child,
+                    tags: [...child.tags, ...testClass.tags],
+                },
+            ];
+        }, [] as TestClass[]),
+    };
+}
+
 /**
  * Updates the existing `vscode.TestItem` if it exists with the same ID as the `TestClass`,
  * otherwise creates an add a new one. The location on the returned vscode.TestItem is always updated.
@@ -203,6 +224,12 @@ export function upsertTestItem(
         deepMergeTestItemChildren(existingItem, newItem);
     }
 
+    // In VS Code tags are not inherited automatically, so if we're recieving a suite we need
+    // to set a suites tag on all of its children. Because test items are added top down the children
+    // aren't updated recursively all at once, but rather one level at a time which then propagages
+    // parent tags down the tree as children are upserted.
+    testItem = applyTagsToChildren(testItem);
+
     // Manually add the test style as a tag so we can filter by test type.
     newItem.tags = [{ id: testItem.style }, ...testItem.tags];
 

test/suite/testexplorer/TestDiscovery.test.ts

@@ -31,14 +31,19 @@ suite("TestDiscovery Suite", () => {
     interface SimplifiedTestItem {
         id: string;
         children: SimplifiedTestItem[];
+        tags: readonly { id: string }[];
     }
 
     function testControllerChildren(collection: vscode.TestItemCollection): SimplifiedTestItem[] {
         return reduceTestItemChildren(
             collection,
             (acc, item) => [
                 ...acc,
-                { id: item.id, children: testControllerChildren(item.children) },
+                {
+                    id: item.id,
+                    tags: [...item.tags.map(tag => ({ id: tag.id }))],
+                    children: testControllerChildren(item.children),
+                },
             ],
             [] as SimplifiedTestItem[]
         );
@@ -77,7 +82,7 @@ suite("TestDiscovery Suite", () => {
         updateTests(testController, [testItem("bar")]);
 
         assert.deepStrictEqual(testControllerChildren(testController.items), [
-            { id: "bar", children: [] },
+            { id: "bar", tags: [{ id: "XCTest" }, { id: "runnable" }], children: [] },
         ]);
     });
 
@@ -109,9 +114,10 @@ suite("TestDiscovery Suite", () => {
         assert.deepStrictEqual(testControllerChildren(testController.items), [
             {
                 id: "foo",
+                tags: [{ id: "XCTest" }, { id: "runnable" }],
                 children: [
-                    { id: "baz", children: [] },
-                    { id: "bar", children: [] },
+                    { id: "baz", tags: [{ id: "XCTest" }, { id: "runnable" }], children: [] },
+                    { id: "bar", tags: [{ id: "XCTest" }, { id: "runnable" }], children: [] },
                 ],
             },
         ]);
@@ -140,7 +146,13 @@ suite("TestDiscovery Suite", () => {
         updateTests(testController, [newFoo]);
 
         assert.deepStrictEqual(testControllerChildren(testController.items), [
-            { id: "foo", children: [{ id: "bar", children: [] }] },
+            {
+                id: "foo",
+                tags: [{ id: "XCTest" }, { id: "runnable" }],
+                children: [
+                    { id: "bar", tags: [{ id: "XCTest" }, { id: "runnable" }], children: [] },
+                ],
+            },
         ]);
         assert.deepStrictEqual(testController.items.get("foo")?.uri, newLocation.uri);
         assert.deepStrictEqual(testController.items.get("foo")?.label, "New Label");
@@ -168,7 +180,57 @@ suite("TestDiscovery Suite", () => {
         updateTestsFromClasses(testController, swiftPackage, [item]);
 
         assert.deepStrictEqual(testControllerChildren(testController.items), [
-            { id: "TestTarget", children: [{ id: "bar", children: [] }] },
+            {
+                id: "TestTarget",
+                tags: [{ id: "test-target" }, { id: "runnable" }],
+                children: [
+                    { id: "bar", tags: [{ id: "XCTest" }, { id: "runnable" }], children: [] },
+                ],
+            },
+        ]);
+    });
+
+    test("Children in suites with tags inherit the suite's tags", async () => {
+        const testSuite = testItem("suite");
+        testSuite.tags = [{ id: "rootTag" }];
+        const childSuite = testItem("childSuite");
+        childSuite.tags = [{ id: "childSuiteTag" }];
+        const childTest = testItem("childTest");
+        childTest.tags = [{ id: "childTestTag" }];
+        childSuite.children = [childTest];
+        testSuite.children = [childSuite];
+
+        updateTests(testController, [testSuite]);
+
+        assert.deepEqual(testControllerChildren(testController.items), [
+            {
+                id: "suite",
+                tags: [{ id: "XCTest" }, { id: "rootTag" }, { id: "runnable" }],
+                children: [
+                    {
+                        id: "childSuite",
+                        tags: [
+                            { id: "XCTest" },
+                            { id: "childSuiteTag" },
+                            { id: "rootTag" },
+                            { id: "runnable" },
+                        ],
+                        children: [
+                            {
+                                id: "childTest",
+                                children: [],
+                                tags: [
+                                    { id: "XCTest" },
+                                    { id: "childTestTag" },
+                                    { id: "childSuiteTag" },
+                                    { id: "rootTag" },
+                                    { id: "runnable" },
+                                ],
+                            },
+                        ],
+                    },
+                ],
+            },
         ]);
     });
 });