yo @theia/plugin gives error TS1005 ',' expected and others

Question

I was looking for developing my own theia plugin. First, I want to try the simple "Hello World" plugin with the command yo @theia/plugin.

Yeoman command to generate Theia plugin

I develop with Ubuntu 20.04. I get many TypeScript errors as we can see in the following image.

Errors with yeoman commands

I tried to figure out by myself. I installed many tsc versions, but nothing worked. I've readed the Prerequisites first and installed every dependencies.

I understand that the TypeScript version may not be the good one, but not sure which one and why.

Here are some versions I use: yarn: 1.22.19 node: v16.14.2 tsc: 3.1.3

Here is the tsconfig file that was autogenetared with yo command:

{
  "compilerOptions": {
    "strict": true,
    "experimentalDecorators": true,
    "noUnusedLocals": true,
    "emitDecoratorMetadata": true,
    "downlevelIteration": true,
    "module": "commonjs",
    "moduleResolution": "node",
    "target": "es6",
    "lib": [
      "es6",
      
      
      "webworker"
      
    ],
    "sourceMap": true,
    "rootDir": "src",
    "outDir": "lib",
    "skipLibCheck": true
  },
  "include": [
    "src"
  ]
}

Here is the package.json:

{
  "name": "hello",
  "publisher": "theia",
  "keywords": [
    "theia-plugin"
  ],
  "version": "0.0.1",
  "license": "none",
  
  "files": [
    "src"
  ],
  "activationEvents": [
    "*"
  ],
  "devDependencies": {
    "@theia/plugin": "next",
    "@theia/plugin-packager": "latest",
    "rimraf": "2.6.2",
    "typescript-formatter": "7.2.2",
    "typescript": "3.5.3"
  },
  "scripts": {
    "prepare": "yarn run clean && yarn run build",
    "clean": "rimraf lib",
    "format-code": "tsfmt -r",
    "watch": "tsc -watch",
    "compile": "tsc", 
    "build": "yarn run format-code && yarn run compile && theia-plugin pack"
  },
  "engines": {
    "theiaPlugin": "next"
  },
  "theiaPlugin": {
    
    
      "backend": "lib/hello-backend.js"
    
  }
}

I changed nothing from the yo command

I am a little lost as why it happens. Can everyone help me out?

I was expecting the yo and yarn commands to be successful.

Edit: As I mentionned as a comment to Konstantin's answer, I ended up using yo theia-extension as mentioned here. It solved my problem. However, I appreciate the answer which helped me fix another problem.

Answer 1

I faced the same issue. It appears the generator's templates are using Typescript syntax not compatible with the bundled TS package. See https://github.com/eclipse/theia-generator-plugin/issues/33#issuecomment-1183227280

Below are the steps to get this up and running, considering a fresh installation. First, install Yeoman globally, as indicated at https://www.npmjs.com/package/@theia/generator-plugin:

npm install -g yo

Next, create a package to hold the generator dependency itself:

mkdir theia-yeoman-sandbox && cd theia-yeoman-sandbox
npm init -y
npm i @theia/generator-plugin

After launching the generator (e.g. Hello World backend plug-in), tsc step fails with the following:

node_modules/@theia/plugin/src/theia.d.ts(5775,60): error TS1005: ',' expected.
node_modules/@theia/plugin/src/theia.d.ts(5775,74): error TS1005: ',' expected.
node_modules/@theia/plugin/src/theia.d.ts(5775,92): error TS1005: ',' expected.
node_modules/@theia/plugin/src/theia.d.ts(5775,93): error TS1109: Expression expected.
...
node_modules/@theia/plugin/src/theia.d.ts(15518,5): error TS1005: ',' expected.
node_modules/@types/node/ts4.8/assert.d.ts(12,72): error TS1144: '{' or ';' expected.
node_modules/@types/node/ts4.8/assert.d.ts(279,72): error TS1144: '{' or ';' expected.
...
node_modules/@types/node/ts4.8/test.d.ts(643,77): error TS1005: ',' expected.
node_modules/@types/node/ts4.8/test.d.ts(647,22): error TS1005: ',' expected.

This can be remediated by upgrading the version of typescript package in plugin's level package.json:

"typescript": "^4.9.5"

Running yarn afterwards emits no error messages and completes just fine:

yarn install v1.22.19
warning package.json: License should be a valid SPDX license expression
warning hello-world@0.0.1: License should be a valid SPDX license expression
[1/5] Validating package.json...
warning hello-world@0.0.1: License should be a valid SPDX license expression
warning hello-world@0.0.1: The engine "theiaPlugin" appears to be invalid.
[2/5] Resolving packages...
[3/5] Fetching packages...
[4/5] Linking dependencies...
warning "@theia/plugin-packager > glob-promise@3.4.0" has unmet peer dependency "glob@*".
[5/5] Building fresh packages...
success Saved lockfile.
$ yarn run clean && yarn run build
yarn run v1.22.19
warning package.json: License should be a valid SPDX license expression
warning hello-world@0.0.1: The engine "theiaPlugin" appears to be invalid.
$ rimraf lib
Done in 0.13s.
yarn run v1.22.19
warning package.json: License should be a valid SPDX license expression
warning hello-world@0.0.1: The engine "theiaPlugin" appears to be invalid.
$ yarn run format-code && yarn run compile && theia-plugin pack
warning package.json: License should be a valid SPDX license expression
warning hello-world@0.0.1: The engine "theiaPlugin" appears to be invalid.
$ tsfmt -r
warning package.json: License should be a valid SPDX license expression
warning hello-world@0.0.1: The engine "theiaPlugin" appears to be invalid.
$ tsc
Packaging of plugin
🔍 Validating...✔️
🗂  Getting dependencies... ✔️
🗃  Resolving files... ✔️
✂️  Excluding files...✔️
✍️  Generating Assembly...✔️
🎉 Generated plugin: hello_world.theia
Done in 6.17s.
Done in 8.42s.

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Node 16.18.1