Pin Express types in TypeScript 3.8 script

dev-packages/node-integration-tests/scripts/use-ts-3_8.js

@@ -1,26 +1,42 @@
 /* eslint-disable no-console */
 const { execSync } = require('child_process');
 const { join } = require('path');
-const { writeFileSync } = require('fs');
+const { readFileSync, writeFileSync } = require('fs');
 
 const cwd = join(__dirname, '../../..');
 
+// Newer versions of the Express types use syntax that isn't supported by TypeScript 3.8.
+// We'll pin to the last version of those types that are compatible.
+console.log('Pinning Express types to old versions...');
+
+const packageJsonPath = join(cwd, 'package.json');
+const packageJson = JSON.parse(readFileSync(packageJsonPath, 'utf8'));
+
+if (!packageJson.resolutions) packageJson.resolutions = {};
+packageJson.resolutions['@types/express'] = '4.17.13';
+packageJson.resolutions['@types/express-serve-static-core'] = '4.17.30';
+
+writeFileSync(packageJsonPath, JSON.stringify(packageJson, null, 2));
+
 const tsVersion = '3.8';
 
 console.log(`Installing typescript@${tsVersion}, and @types/node@14...`);
 
-execSync(`yarn add --dev --ignore-workspace-root-check typescript@${tsVersion} @types/node@^14`, {
-  stdio: 'inherit',
-  cwd,
-});
+execSync(
+  `yarn add --dev --ignore-workspace-root-check typescript@${tsVersion} @types/node@^14 @types/[email protected] @types/[email protected]`,
+  {
+    stdio: 'inherit',
+    cwd,
+  },
+);
 
 console.log('Removing unsupported tsconfig options...');
 
 const baseTscConfigPath = join(cwd, 'packages/typescript/tsconfig.json');
 
 const tsConfig = require(baseTscConfigPath);
 
-// TS 3.8 fails build when it encounteres a config option it does not understand, so we remove it :(
+// TS 3.8 fails build when it encounters a config option it does not understand, so we remove it :(
 delete tsConfig.compilerOptions.noUncheckedIndexedAccess;
 
 writeFileSync(baseTscConfigPath, JSON.stringify(tsConfig, null, 2));