Keep self-hosting test workers responsive during compilation

- Run runtime-pack and native-toolchain compiler passes in child processes.
- Preserve static coverage and native behavior assertions without relying on an unsupported RPC timeout setting.

.github/workflows/ci.yml

@@ -22,8 +22,6 @@ jobs:
       # calling onTaskUpdate") with every test green — the same contention
       # artifact the harness README documents for local parallel suites.
       SCRIPTC_TEST_WORKERS: "4"
-      # Native self-hosting analysis can block worker RPC during lowering.
-      VITEST_RPC_TIMEOUT: "180000"
       # san = ASan + RC audit over the same suite; anything but "1" is plain.
       SCRIPTC_SAN: ${{ matrix.flavor == 'san' && '1' || '' }}
       # Within-file partition for the large case-driven harnesses

tests/harness/self-hosting-compiler-process.ts

@@ -0,0 +1,37 @@
+import { execFile } from "node:child_process";
+import { fileURLToPath } from "node:url";
+import { promisify } from "node:util";
+import type { AnalyzeOptions, CompileOptions, CompileExecutableResult, CoverageInput } from "@scriptc/compiler";
+
+const execFileAsync = promisify(execFile);
+const root = fileURLToPath(new URL("../../", import.meta.url));
+const api = new URL("../../packages/compiler/src/index.ts", import.meta.url).href;
+
+// Large synchronous frontend passes must leave Vitest's worker RPC responsive.
+// Execute the source API in a child and return only JSON-compatible results.
+async function compilerProcess(operation: "analyze" | "compile", entry: string, options: object): Promise<unknown> {
+  const { stdout, stderr } = await execFileAsync(process.execPath, [
+    "--max-old-space-size=8192", "--import", "tsx", "--input-type=module", "--eval",
+    `import { analyze, compile } from ${JSON.stringify(api)};
+     const options = JSON.parse(process.argv[3]);
+     const result = process.argv[1] === 'analyze'
+       ? analyze(process.argv[2], options).coverage
+       : await compile(process.argv[2], options);
+     console.log(JSON.stringify(result, (key, value) => key === 'sourceTexts' ? undefined : value));`,
+    operation, entry, JSON.stringify(options),
+  ], { cwd: root, timeout: 300_000, maxBuffer: 16 * 1024 * 1024 });
+  if (stderr !== "") throw new Error(stderr);
+  return JSON.parse(stdout);
+}
+
+export async function analyzeInChild(entry: string, options: AnalyzeOptions): Promise<CoverageInput> {
+  return await compilerProcess("analyze", entry, options) as CoverageInput;
+}
+
+type ExecutableResult =
+  | Extract<CompileExecutableResult, { ok: true }>
+  | Omit<Extract<CompileExecutableResult, { ok: false }>, "sourceTexts">;
+
+export async function compileInChild(entry: string, options: CompileOptions): Promise<ExecutableResult> {
+  return await compilerProcess("compile", entry, options) as ExecutableResult;
+}

tests/harness/self-hosting-native-toolchain.test.ts

@@ -4,7 +4,7 @@ import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { expect, test } from "vitest";
-import { analyze, compile } from "@scriptc/compiler";
+import { analyzeInChild, compileInChild } from "./self-hosting-compiler-process.js";
 import { nativeCodegenTarget } from "../../packages/compiler/src/backend/targets.js";
 import type { NativeLinkFeatures } from "../../packages/compiler/src/backend/native-link-info.js";
 import type { RuntimePackManifest } from "../../packages/compiler/src/backend/runtime-pack-core.js";
@@ -20,8 +20,8 @@ const features: NativeLinkFeatures = {
   http2: false, dgram: false, watch: false, foreignFfi: false, nodeTest: false, tls: false, tlsCa: false,
 };
 
-test("native toolchain configuration, staging and helper validation are static", () => {
-  const { coverage } = analyze(entry, { dynamic: false });
+test("native toolchain configuration, staging and helper validation are static", async () => {
+  const coverage = await analyzeInChild(entry, { dynamic: false });
   expect(coverage.preflightFailed).toBe(false);
   expect(coverage.stats.statementsFailed).toBe(0);
   expect(coverage.stats.statementsIsland).toBe(0);
@@ -33,7 +33,7 @@ for (const backend of ["llvm"] as const) {
     const directory = mkdtempSync(join(process.platform === "win32" ? tmpdir() : "/tmp", "scriptc-native-integrity-"));
     const target = nativeCodegenTarget()!;
     try {
-      const built = await compile(entry, {
+      const built = await compileInChild(entry, {
         outDir: directory, outPath: join(directory, "toolchain" + target.outputSuffixes.exe),
         backend, optimization: "dev", dynamic: false, sanitize: process.env["SCRIPTC_SAN"] === "1",
       });

tests/harness/self-hosting-runtime-pack.test.ts

@@ -3,7 +3,7 @@ import { mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { expect, test } from "vitest";
-import { analyze, compile } from "@scriptc/compiler";
+import { analyzeInChild, compileInChild } from "./self-hosting-compiler-process.js";
 import { NATIVE_TARGETS, nativeCodegenTarget } from "../../packages/compiler/src/backend/targets.js";
 import type { NativeLinkFeatures } from "../../packages/compiler/src/backend/native-link-info.js";
 import type { RuntimePackManifest } from "../../packages/compiler/src/backend/runtime-pack-core.js";
@@ -18,8 +18,8 @@ const base: NativeLinkFeatures = {
   http2: false, dgram: false, watch: false, foreignFfi: false, nodeTest: false, tls: false, tlsCa: false,
 };
 
-test("runtime manifest validation and selection are entirely static", () => {
-  const { coverage } = analyze(entry, { dynamic: false });
+test("runtime manifest validation and selection are entirely static", async () => {
+  const coverage = await analyzeInChild(entry, { dynamic: false });
   expect(coverage.preflightFailed).toBe(false);
   expect(coverage.stats.statementsTotal).toBeGreaterThan(50);
   expect(coverage.stats.statementsFailed).toBe(0);
@@ -31,7 +31,7 @@ for (const backend of ["llvm"] as const) {
   test(`native runtime manifest selection matches Node (${backend})`, async () => {
     const directory = mkdtempSync(join(process.platform === "win32" ? tmpdir() : "/tmp", "scriptc-pack-selection-"));
     try {
-      const built = await compile(entry, {
+      const built = await compileInChild(entry, {
         outDir: directory, outPath: join(directory, "selection" + (process.platform === "win32" ? ".exe" : "")),
         backend, dynamic: false, optimization: "dev", sanitize: process.env["SCRIPTC_SAN"] === "1",
       });