### Instructions

- You can run execution tests by doing ./scripts/exec.sh to see if your changes are working.
- If an execution test fails, you are wrong.
- Always run execution tests after making changes.
- You can run fixture tests by doing ./scripts/test.sh, and you can do UPDATE=1 ./scripts/test.sh to update fixtures.

### Minifier Semantic Assumptions

The ECMAScript minifier may rely on the documented assumptions from the SWC
minification guide:

- Calls to primitive coercion helpers such as `toString` and `valueOf` are
  side-effect free, and built-in object implementations have not been
  overridden.
- `undefined`, `NaN`, and `Infinity` have not been externally redefined.
- `arguments.callee`, `arguments.caller`, and `Function.prototype.caller` are
  not used.
- Code does not depend on the exact contents of `Function.prototype.toString()`
  or `Error.prototype.stack`.
- Getting or setting properties on a plain object does not trigger side effects
  through `watch`, `Proxy`, or similar mechanisms.
- Object properties can be added, removed, and modified unless the change is
  intentionally handling frozen, sealed, non-extensible, or descriptor-locked
  objects.
- `document.all` is treated as not `null`.
- Assigning properties to classes is assumed to be side-effect free and
  non-throwing.
- Accessing declared top-level identifiers is assumed to be side-effect free.
- TDZ violations are not preserved.
- Arithmetic expressions are treated as side-effect free, including runtime
  exceptions such as mixing `bigint` and `number`.

If a minifier change relies on an assumption beyond this list, update the
public minification documentation or leave an explicit code comment describing
the narrower local invariant.

### Fixture Test Addition Guide

- Preferred fixture roots in this crate: tests/fixture, tests/mangle, tests/pass-1, tests/pass-default, tests/full, tests/projects, benches/full.
- Do not add new regression coverage to tests/terser. Use SWC-owned fixtures such as tests/fixture/issues instead.
- Update generated fixture outputs with: UPDATE=1 cargo test -p swc_ecma_minifier.
- Verify without UPDATE before finishing: cargo test -p swc_ecma_minifier.