sourcesContent only added to build options not transform options in JS API

[jschaf]

The docs (https://esbuild.github.io/api/#sources-content) list sourcesContent as a valid option for both transform and build but the code for the JS API defines sourcesContent only for build flags:

esbuild/lib/common.ts

Line 164 in 08ca8cf

let sourcesContent = getFlag(options, keys, 'sourcesContent', mustBeBoolean);

This means esbuild will error when you specify sourcesContent: false for the transform API:

  const esbuildOpts = {
    format: 'cjs',
    target: 'esnext',
    loader: loader,
    sourcemap: true,
    sourcesContent: false,
    sourcefile: sourcePath,
  };
  const result = esbuild.transformSync(sourceText, esbuildOpts);

Errors with:

Invalid option in transformSync() call: "sourcesContent"