cmd/pkgserver: add JSON reporter to facilitate go test integration

cmd/pkgserver/ui/static/test.ts

@@ -84,6 +84,7 @@ export interface TestResult {
 }
 
 export function run(reporter: Reporter) {
+    reporter.register(TESTS);
     for (const suite of TESTS) {
         for (const c of suite.children) runTests(reporter, [suite.name], c);
     }
@@ -122,6 +123,7 @@ function extractExceptionString(e: any): string {
 // Reporting
 
 export interface Reporter {
+    register(suites: TestGroup[]): void
     update(path: string[], result: TestResult): void;
     finalize(): void;
 }
@@ -145,6 +147,8 @@ export class StreamReporter implements Reporter {
         this.counts = { successes: 0, failures: 0 };
     }
 
+    register(suites: TestGroup[]) {}
+
     update(path: string[], result: TestResult) {
         if (path.length === 0) throw new RangeError("path is empty");
         const pathStr = path.join(SEP);
@@ -202,6 +206,8 @@ export class StreamReporter implements Reporter {
 }
 
 export class DOMReporter implements Reporter {
+    register(suites: TestGroup[]) {}
+
     update(path: string[], result: TestResult) {
         if (path.length === 0) throw new RangeError("path is empty");
         const counter = document.getElementById(result.success ? "successes" : "failures");
@@ -246,3 +252,31 @@ export class DOMReporter implements Reporter {
 
     finalize() {}
 }
+
+interface GoNode {
+    name: string;
+    subtests?: GoNode[];
+}
+
+// Used to display results via `go test`, via some glue code from the Go side.
+export class GoTestReporter implements Reporter {
+    // Convert a test tree into the one expected by the Go code.
+    static serialize(node: TestTree): GoNode {
+        return {
+            name: node.name,
+            subtests: "children" in node ? node.children.map(GoTestReporter.serialize) : null,
+        };
+    }
+
+    register(suites: TestGroup[]) {
+        console.log(JSON.stringify(suites.map(GoTestReporter.serialize)));
+    }
+
+    update(path: string[], result: TestResult) {
+        console.log(JSON.stringify({ path: path, ...result }));
+    }
+
+    finalize() {
+        console.log("null");
+    }
+}