Support ts-node app driver

[ccurrie-amzn]

Instead of requiring a build step to convert the Typescript code to javascript, it would help development cycle time if cdk.json could say something like:

{
  "app": "ts-node bin/deploy.ts"
}

[rix0rrr]

Why does this not work? Or is this issue about making it the default via init templates?

[rix0rrr]

(My question is: why is this a ticket?)

[eladb]

I think it's a proposed improvement on our current template/guidelines to use "node" and require users to have a separate compile step...

[ccurrie-amzn]

If I take a brand new project from cdk init, run npm i -D ts-node, and change cdk.json to:

{
   "app": "npx ts-node bin/test_cdk.ts"
}

When I run cdk synth I get Cannot parse request 'Projects/testCdk/bin/test_cdk.ts': Unexpected token / in JSON at position 0.

[eladb]

I can see what’s going on here. Since you are using ts-node, this code doesn’t take effect.

The good news is that I am working on getting rid of the argv protocol (#216) as we speak so hopefully soon this won’t be an issue.

[rix0rrr]

Does it work now in 0.12.0?

[ccurrie-amzn]

Yes it does! Thanks.

[mikecann]

ts-node doesnt work for me (as of CDK 0.19.0) has something changed?

The error I get is:

spawn npx ENOENT
Error: spawn npx ENOENT
    at _errnoException (util.js:992:11)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:190:19)
    at onErrorNT (internal/child_process.js:372:16)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)

[eladb]

Seems like the toolkit can't find npx on your system. What node.js version are you using?

I verified the following configuration works with 0.19.0 and node.js v10.13.0:

cdk.json

{
  "app": "npx ts-node bin/hello-cdk.ts"
}

package.json:

{
  "devDependencies": {
    "@types/node": "^8.9.4",
    "aws-cdk": "^0.19.0",
    "ts-node": "^7.0.1",
    "typescript": "^3.1.2"
  },
  "dependencies": {
    "@aws-cdk/cdk": "^0.19.0"
  }
}

[mikecann]

hmm wierd..

npx -v

npx: installed 1 in 1.624s
Path must be a string. Received undefined
9.7.1

node -v

v8.11.3

package.json:

{
  "name": "my_widget_service",
  "version": "0.1.0",
  "bin": {
    "my_widget_service": "bin/my_widget_service.js"
  },
  "scripts": {
    "build": "tsc",
    "watch": "tsc -w",
    "cdk": "cdk",
    "ts-node": "ts-node"
  },
  "devDependencies": {
    "@types/node": "^8.9.4",
    "aws-cdk": "^0.19.0",
    "ts-node": "^7.0.1",
    "typescript": "^3.1.2"
  },
  "dependencies": {
    "@aws-cdk/aws-apigateway": "^0.19.0",
    "@aws-cdk/aws-lambda": "^0.19.0",
    "@aws-cdk/aws-s3": "^0.19.0",
    "@aws-cdk/cdk": "^0.19.0"
  }
}

cdk.json

{
  "app": "npx ts-node bin/my_widget_service.ts"
}

then

npx cdk deploy

npx: installed 1 in 1.568s
Path must be a string. Received undefined
C:\dev\bam\experiments\MyWidgetService\node_modules\aws-cdk\bin\cdk
spawn ts-node ENOENT

I usually use yarn not npx, so lets give that a try:

I changed cdk.json to

{
  "app": "yarn ts-node bin/my_widget_service.ts"
}

then

yarn cdk deploy

$ cdk deploy
spawn yarn ENOENT
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

trying

yarn cdk deploy -v

$ yarn cdk deploy -vyarn run v1.9.4
warning package.json: No license field
$ cdk deploy -vCDK toolkit version: 0.19.0 (build 2625a05)Command line arguments: { _: [ 'deploy' ], trace: false,
strict: false,
'ignore-errors': false,
ignoreErrors: false,
json: false,
j: false,
verbose: true,
v: true,
ec2creds: undefined,
i: undefined,
'version-reporting': undefined,
versionReporting: undefined,
'path-metadata': true,
pathMetadata: true,
version: false,
help: false,
h: false,
'role-arn': undefined,
r: undefined,
roleArn: undefined,
'$0': 'node_modules\aws-cdk\bin\cdk',
app: undefined,
context: undefined,
plugin: undefined,
rename: undefined,
profile: undefined,
proxy: undefined,
'toolkit-stack-name': undefined,
STACKS: [] }
Determining whether we're on an EC2 instance.
cdk.json: {
"app": "yarn ts-node bin/my_widget_service.ts"
}
Setting "aws:cdk:toolkit:default-region" context to ap-southeast-2
Resolving default credentials
Does not look like EC2 instance.
Looking up default account ID from STS
Default account ID: 385936341354
Setting "aws:cdk:toolkit:default-account" context to 385936341354
context: { 'aws:cdk:toolkit:default-region': 'ap-southeast-2',
'aws:cdk:toolkit:default-account': '385936341354',
'aws:cdk:enable-path-metadata': true }
outdir: C:\Users\mikec\AppData\Local\Temp\cdkqD4uPl
Removing outdir C:\Users\mikec\AppData\Local\Temp\cdkqD4uPl
spawn yarn ENOENT
Error: spawn yarn ENOENT
at _errnoException (util.js:992:11)
at Process.ChildProcess._handle.onexit (internal/child_process.js:190:19)
at onErrorNT (internal/child_process.js:372:16)
at _combinedTickCallback (internal/process/next_tick.js:138:11)
at process._tickDomainCallback (internal/process/next_tick.js:218:9)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

If I try running the TS file directly it runs okay:

yarn ts-node bin/my_widget_service.ts

ERROR: The environment variable "CDK_OUTDIR" is not defined
AWS CDK Toolkit (>= 0.11.0) is required in order to interact with this program.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

So im out of ideas now...

[rix0rrr]

I think the missing piece of information here was "Windows".

Your npx executable probably ends up being called npx.bat or npx.cmd. If you just type npx on the command-line, cmd.exe is going to try all the possible extensions, but our launcher won't. Try updating your cdk.json to:

{
  "app": "npx.bat ts-node bin/my_widget_service.ts"
}

(Or npx.cmd... or maybe it's even npx.js?)

[mikecann]

@rix0rrr wow ye! I am running in the git bash shell in windows so I am surprised that there is a difference but indeed running npx.cmd ts-node bin/my_widget_service.ts or yarn.cmd ts-node bin/my_widget_service.ts works!

Thanks for all you assistance guys, I hope this helps other future googlers too 😉

[rix0rrr]

Oh, that confuses me too then. But it might be that the bash shell for Windows has the same behavior as cmd built-in? Anyway, glad it works for you.

[mikecann]

@rix0rrr sorry to keep going on about this mate, but although the "add .cmd" works on windows it doesnt work on osx or linux. On those platforms you can just do "npx" or "yarn" without the ".cmd" which is annoying as I want a consistent build command on all platforms. Any idea if there is a way around this?

[rix0rrr]

Offhand, making an executable yarn.cmd file that you only put on the $PATH in Linux will work. Potentially in everyone's home directory? Obviously, not a fantastic solution but it would work.

Let me think about other solutions.

[rix0rrr]

An alternative is we run the command through the shell on Windows... but that opens up a host of potential shell quoting issues that I really don't want to be responsible for. Will crop up easily in a directory with spaces, not to mention that quoted argument parsing in Windows is unpredictable and depends on a complicated dance between OS and userspace code.

[mikecann]

I am experimenting around with run-script-os lets me do:

    "cdk": "run-script-os",
    "cdk:win32": "cdk --app \"npm.cmd run ts-node -P tsconfig-cdk.json cdk/index.ts\"",
    "cdk:darwin:linux": "cdk --app \"npm run ts-node -P tsconfig-cdk.json cdk/index.ts\"",

It works, but it feels like it should be part of cdk somehow..

[mikecann]

@rix0rrr what do you think? Should we reopen this issue because it would be nice to have a cross-platform solution as the extra CDK compilation step with TS really shouldnt be needed..

[rix0rrr]

Sure, let's reopen

[rix0rrr]

Okay, too much detritus in this ticket. I'll create a new one