cds-plugin-typescript

cds-plugin-typescript

A CDS build plugin for SAP CAP that compiles TypeScript sources to JavaScript as part of cds build.

It is similar to cds-typer but focused exclusively on TypeScript compilation. It also supports resolving TypeScript path aliases via tsc-alias.

Prerequisites

• Node.js >=22
• npm >=10
• @sap/cds >=8
• typescript >=5
• tsc-alias >=1 (optional — automatically detected and used if listed in your project's package.json)

Installation

npm install --save-dev cds-plugin-typescript

Usage

Once installed, the plugin is automatically discovered and activated — no manual registration needed. It's a cds-plugin and will be loaded by CAP automatically.

Simply run cds build and the plugin will:

1. Detect your tsconfig file (see tsconfig resolution below)
2. Compile TypeScript sources with tsc
3. Resolve path aliases with tsc-alias (automatic — runs if tsc-alias is found in your project's dependencies or devDependencies)
4. Remove .ts source files from the build output

Configuration

Zero configuration is required by default. Simply:

1. Install the plugin (npm install --save-dev cds-plugin-typescript)
2. Maintain a tsconfig file — the plugin automatically looks for tsconfig.cdsbuild.json, tsconfig.build.json, or tsconfig.json (first found wins)
3. Run cds build

That's it — no package.json changes needed.

Custom tsConfig path

The cds.build.tasks configuration in package.json is only needed if you want to point the plugin at a tsconfig file with a non-standard name (i.e. something other than the three files listed above):

{
  "cds": {
    "build": {
      "tasks": [
        { "for": "nodejs" },
        {
          "for": "typescript",
          "options": {
            "tsConfig": "tsconfig.custom.json"
          }
        }
      ]
    }
  }
}

tsconfig resolution

The plugin resolves the tsconfig file using the following priority order:

1. Custom path via the tsConfig option (if provided in the build task configuration)
2. tsconfig.cdsbuild.json — a CDS-build-specific config
3. tsconfig.build.json — a general build-specific config
4. tsconfig.json — the standard TypeScript config

The plugin uses the first file found in this order. This allows you to maintain separate TypeScript configurations for CDS builds, general builds, and development without conflicts.

The default/recommended tsconfig for the default CDS folder structure is:

{
  "compilerOptions": {
    "rootDir": "srv",
    "outDir": "gen/srv/srv",
    "declaration": true,
    "sourceMap": true,
    "removeComments": true
  },
  "include": [
    "srv/**/*"
  ]
}

The outDir in your tsconfig determines where compiled output lands — make sure it aligns with your CDS build target (default: gen).

Path aliases

If your project uses TypeScript path aliases (e.g. @/* → src/*), simply add tsc-alias to your project's dependencies or devDependencies:

npm install --save-dev tsc-alias

The plugin automatically detects whether tsc-alias is listed in your package.json (under dependencies or devDependencies) and runs it after tsc to rewrite the aliases in the compiled JavaScript. No additional configuration is needed.

If tsc-alias is not listed in your package.json, the path alias resolution step is skipped entirely.

How it works

The plugin extends cds.build.Plugin and is registered under the task type typescript.

Build steps:

1. Resolve the tsconfig path (priority: tsConfig option → tsconfig.cdsbuild.json → tsconfig.build.json → tsconfig.json)
2. Run npx tsc -p <tsconfig> from the task source directory — logs: "Compiling TypeScript using <tsconfig>"
3. If tsc-alias is detected in package.json: run npx tsc-alias -p <tsconfig> — logs: "Resolving path aliases"
4. Delete all .ts files (excluding .d.ts) from the build output — logs: "Removing TypeScript sources"

Clean step:

cds build --clean removes all .js and .map files emitted by this plugin from the destination directory.

TypeScript 7

TypeScript 7.0 is a native Go port and does not ship with a programmatic API yet. Tools that rely on import('typescript') (such as tsc-alias, typescript-eslint, and CAP itself) still need the TypeScript 6 API.

Microsoft provides a compatibility package @typescript/typescript6 that re-exports the TypeScript 6 API but renames its binary to tsc6, allowing TypeScript 6 and 7 to coexist. You can install both via npm aliases so that npx tsc uses TypeScript 7 while tooling that calls import('typescript') gets the TypeScript 6 API:

{
  "devDependencies": {
    "@typescript/native": "npm:typescript@^7.0.2",
    "typescript": "npm:@typescript/typescript6@^6.0.2"
  }
}

This plugin works with this setup out of the box — it shells out to npx tsc (TypeScript 7) and detects tsc-alias in your package.json (which continues to use the TypeScript 6 API transparently).

Related

• CAP Custom Build Tasks
• CDS Build API
• cds-typer
• tsc-alias

License

MIT