fix(init): TypeScript code is not being recompiled automatically (#11470

) The use of `npx ts-node` to run the app in the TypeScript init templates is intended to make sure the source code gets transpiled before every synth without the user needing to `npm run build` explicitly. I have had reports on the Hello World dev guide topic that an `npm run build` is still needed, even though it shouldn't be. I was able to reproduce this issue today (was not able to do so previously). The problem is that, by default, `ts-node` prefers resolving imports to JavaScript files. If a JavaScript file exists, as it would be after the first build, it is simply imported as-is. The corresponding TypeScript module is not transpiled. Therefore changes you make to the TS code are never picked up and stale JS code is used. The flag `--prefer-ts-exts` solves this issue. It causes module imports to prefer importing TypeScript files, which means that the modules will get recompiled if necessary. ---- *By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*
aws · Nov 17, 2020 · 9843e71 · 9843e71
1 parent 989d15f
commit 9843e71
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diff --git a/packages/aws-cdk/lib/init-templates/app/typescript/cdk.template.json b/packages/aws-cdk/lib/init-templates/app/typescript/cdk.template.json
@@ -1,3 +1,3 @@
 {
-  "app": "npx ts-node bin/%name%.ts"
+  "app": "npx ts-node --prefer-ts-exts bin/%name%.ts"
 }
diff --git a/packages/aws-cdk/lib/init-templates/app/typescript/package.template.json b/packages/aws-cdk/lib/init-templates/app/typescript/package.template.json
@@ -17,7 +17,7 @@
     "jest": "^26.4.2",
     "ts-jest": "^26.2.0",
     "aws-cdk": "%cdk-version%",
-    "ts-node": "^8.1.0",
+    "ts-node": "^8.3.0",
     "typescript": "~3.9.7"
   },
   "dependencies": {

diff --git a/packages/aws-cdk/lib/init-templates/sample-app/typescript/cdk.template.json b/packages/aws-cdk/lib/init-templates/sample-app/typescript/cdk.template.json
@@ -1,3 +1,3 @@
 {
-  "app": "npx ts-node bin/%name%.ts"
+  "app": "npx ts-node --prefer-ts-exts bin/%name%.ts"
 }
diff --git a/packages/aws-cdk/lib/init-templates/sample-app/typescript/package.template.json b/packages/aws-cdk/lib/init-templates/sample-app/typescript/package.template.json
@@ -17,7 +17,7 @@
     "@types/node": "10.17.27",
     "jest": "^26.4.2",
     "ts-jest": "^26.2.0",
-    "ts-node": "^8.1.0",
+    "ts-node": "^8.3.0",
     "typescript": "~3.9.7"
   },
   "dependencies": {