typescript-cached-transpile

typescript-cached-transpile

Monkey-patches the TypeScript compiler to use a disk cache for transpileModule.

Intended for use solely with ts-node in transpileOnly mode. It'll make things faster.

TS_NODE_TRANSPILE_ONLY=true TS_NODE_COMPILER=typescript-cached-transpile ts-node ./src/index.ts

When required, it returns a monkey-patched version of the peer typescript module. The only change is the transpileModule function. It will cache results on disk, so subsequent invocations should be much faster.

Caching requires, and will only work, when the following requirements are met. If these requirements are not met, caching will be silently skipped. If you wonder why your builds aren't getting faster, you might be violating these requirements.

• no transformers
• no diagnostics returned by the compiler
• compiler version is the same
• filename is the same
• source code is the same
• sourcemaps are enabled
• config object is the same, as determined by serializing to JSON and sha1 hashing
• using transpileModule. Won't work if you're type-checking. (do that separately, e.g. tsc --noEmit)

If you need to programmatically customize the behavior, put your customizations in a JS file:

./my-cached-compiler.js
const {create} = require('typescript-cached-transpile');
module.exports = create({
    /* options here */
});

...and pass the absolute path to that file as ts-node's compiler option.

TS_NODE_TRANSPILE_ONLY=true TS_NODE_COMPILER=$PWD/my-cached-compiler.js ts-node ./src/index.ts

The cache directory can be set via environment variable TS_CACHED_TRANSPILE_CACHE. It should be an absolute path to avoid gotchas.

TS_NODE_TRANSPILE_ONLY=true TS_CACHED_TRANSPILE_CACHE=$PWD/.cache ts-node ./src/index.ts

Portable / pre-compiled cache

Filenames are included in the cache keys. Normally these are absolute. If you want to bundle a pre-generated cache with your code, the cache will need to use relative paths instead. Set env var TS_CACHED_TRANSPILE_PORTABLE to true to enable this behavior.