esbuild-ctor-param-decorator-bug-sample

The build result of the decorator given to the constructor parameters is different between tsc and esbuild(v0.8.38). This repository presents an example of using the Inversify.js decorator.

Caution

This bug has been fixed in esbuild v0.8.40.

evanw/esbuild#734

How to use

1. Run npm install.

2. Run npm run build. The code built by tsc will be output to dist, and the code built by esbuild will be output to dist_esbuild.

3. Run npm run start:tsc. The decorator will be recognized correctly and "cut!" will be output to the console.

4. Run npm run start:esbuild. It does not work properly and the following error occurs.

/path/to/node_modules/inversify/lib/annotation/decorator_utils.js:21
        throw new Error(ERROR_MSGS.INVALID_DECORATOR_OPERATION);
        ^

Error: The @inject @multiInject @tagged and @named decorators must be applied to the parameters of a class constructor or a class property.
    at _tagParameterOrProperty (/path/to/node_modules/inversify/lib/annotation/decorator_utils.js:21:15)
    at Object.tagParameter (/path/to/node_modules/inversify/lib/annotation/decorator_utils.js:8:5)
    at /path/to/node_modules/inversify/lib/annotation/inject.js:25:31
    at /path/to/dist_esbuild/container.js:36:54
    at __decorate (/path/to/dist_esbuild/container.js:31:24)
    at Object.<anonymous> (/path/to/dist_esbuild/container.js:78:1)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)

Why does the error occur?

You can find the cause by comparing these two files.

• dist/src/container.js
• dist_esbuild/container.js

The decorator in the constructor parameter of the Ninja class is handled differently.

// in dist/src/container.js
Ninja = __decorate([
    inversify_1.injectable(),
    __param(0, inversify_1.inject(exports.Symbols.Katana)),
    __param(1, inversify_1.inject(exports.Symbols.Shuriken))
], Ninja);

// in dist_esbuild/container.js
__decorate([
  __param(0, import_inversify.inject(Symbols.Katana)),
  __param(1, import_inversify.inject(Symbols.Shuriken))
], Ninja.prototype, "constructor", 1);
Ninja = __decorate([
  import_inversify.injectable()
], Ninja);

This problem can be fixed by modifying the above code in dist_esbuild/container.js as follows.

Ninja = __decorate([
  import_inversify.injectable(),
  __param(0, import_inversify.inject(Symbols.Katana)),
  __param(1, import_inversify.inject(Symbols.Shuriken))
], Ninja);