Attempt at speeding up prisma-generator tests

.gitignore

@@ -8,3 +8,4 @@ dist
 coverage
 .build
 .test
+/.pnpm-test-store

packages/schema/tests/generator/prisma-generator.test.ts

@@ -6,22 +6,29 @@ import path from 'path';
 import tmp from 'tmp';
 import { loadDocument } from '../../src/cli/cli-util';
 import { PrismaSchemaGenerator } from '../../src/plugins/prisma/schema-generator';
-import { execSync } from '../../src/utils/exec-utils';
 import { loadModel } from '../utils';
+import { preparePackageJson, initProjectDir } from '../../../../script/test-utils';
 
 tmp.setGracefulCleanup();
 
 describe('Prisma generator test', () => {
     let origDir: string;
 
+    let packageJsonContents: string;
+
+    beforeAll(async () => {
+        packageJsonContents = preparePackageJson({
+            'prisma': '^5.0.0'
+        });
+    })
+
     beforeEach(() => {
         origDir = process.cwd();
         const r = tmp.dirSync({ unsafeCleanup: true });
-        console.log(`Project dir: ${r.name}`);
+        console.log('Project dir: ', r.name);
         process.chdir(r.name);
 
-        execSync('npm init -y', { stdio: 'ignore' });
-        execSync('npm install prisma');
+        initProjectDir(r.name, packageJsonContents);
     });
 
     afterEach(() => {

script/test-utils.ts

@@ -0,0 +1,56 @@
+import path from 'node:path';
+import fs from 'node:fs';
+import { tmpdir } from 'node:os';
+import { execSync } from 'node:child_process';
+
+export const PNPM_STORE_PATH = path.resolve(__dirname, '../.pnpm-test-store');
+export const NPM_RC_FILE = '.npmrc';
+export const NPM_RC_CONTENTS = `store-dir = ${PNPM_STORE_PATH}`;
+export const PACKAGE_JSON_FILE = 'package.json';
+export const PACKAGE_JSON_CONTENTS = '{"name":"test-project","version":"1.0.0"}';
+
+export function preparePackageJson(dependencies: {[key: string]: string} = {}, devDependencies: {[key: string]: string} = {}): string {
+  // Given that this is a loose file included from elsewhere, I couldn't rely on the tmp package here and had to go with built-in node functions. I saw no significant downsides in this case, versus the upside in developer experience of not needing to do a build step when changing these utils.
+  const tmpDir = fs.mkdtempSync(path.join(tmpdir(), 'zenstack-test-'));
+  console.log(`Loading dependencies into store via temp dir ${tmpDir}`);
+  try {
+  const packageJsonContents = 
+`{
+  "name":"test-project",
+  "version":"1.0.0",
+  "dependencies": {
+    ${Object.entries(dependencies).map(([k, v]) => `"${k}": "${v}"`).join(',\n')}
+  },
+  "devDependencies": {
+    ${Object.entries(devDependencies).map(([k, v]) => `"${k}": "${v}"`).join(',\n')}
+  }
+}`;
+
+  // I considered doing a `pnpm store add` here instead of a plain install. While that worked, I decided against it in the end because it's a secondary way of processing the dependencies and I didn't see a significant downside to just installing and throwing the local project away right after.
+  initProjectDir(tmpDir, packageJsonContents, false);
+
+  return packageJsonContents;
+  } finally {
+    fs.rmSync(tmpDir, {recursive: true, force: true});
+  }
+}
+
+export function initProjectDir(projectDir: string, packageJsonContents: string, offline = true) {
+  try {
+    if (!fs.existsSync(projectDir)) {
+      fs.mkdirSync(projectDir, { recursive: true });
+    }
+    fs.writeFileSync(path.join(projectDir, PACKAGE_JSON_FILE), packageJsonContents, { flag: 'w+' });
+    fs.writeFileSync(path.join(projectDir, NPM_RC_FILE), NPM_RC_CONTENTS, { flag: 'w+' });
+  } catch (e) {
+    console.error(`Failed to set up project dir in ${projectDir}`);
+    throw e;
+  }
+
+  try {
+    execSync(`pnpm install ${offline ? '--offline ' : ''}--ignore-workspace`, {cwd: projectDir, stdio: 'ignore'});
+  } catch (e) {
+    console.error(`Failed to initialize project dependencies in ${projectDir}${offline ? '(offline mode)' : '(online mode)'}`);
+    throw e;
+  }
+}