Limitations

Harmony changes compiled runtime code, so its guarantees stop at explicit boundaries.

Patch modules

Provider Patch files must be CommonJS modules. Harmony's live Loader update path collects them synchronously.

Compiled structure

Source selectors depend on the compiled shape of the target package. A target upgrade may change names, nesting, JSX output, or bundler helpers without changing the visible feature. Pin a compatible target.version, keep expect exact, and run dsh harmony status in release checks.

Semantic targets

Semantic Patches support named function declarations and class methods. Parameters must be named identifiers; generators are not supported.

Semantic handlers execute in Node.js. Browser bundles such as lib/client.js require Source Patches.

Only one enabled semantic replace Patch may target a function. A conflicting transaction is rejected.

Provider order

before and after are preferences over provider package names. Contradictory constraints may have no perfect order; automatic sorting minimizes violations but does not override the manual list.

conflicts produces a warning, not an installation or runtime block.

Runtime ownership

Harmony does not:

• mutate installed target files;
• proxy WebUI traffic;
• provide a second Host or session store;
• make a global installation affect an upstream Desktop that starts its own built-in CLI directly;
• infer whether two arbitrary source transformations are semantically compatible.