- #1634 bars variables with cross-scope references in between to collapse
- but if assigned value is side-effect-free, no states can be modified, so it is safe to move
- mention performance anomaly in Node 7 and drop from CI
- remove unused npm "scripts"
- mark browserify dependency as optional
- stop `test/mozilla-ast.js` from spamming console output in later versions of Node.js
That particular version of Node.js has messed up error messages, so provide a version-specific workaround.
Also fixed an formatting issue which would cause `expect_stdout` to fail if error message contains excerpts of input.
Apply `expect_stdout` to more applicable tests.
The following is wrong:
`a == (b ? a : c)` => `b`
Because:
- `b` may not be boolean
- `a` might have side effects
- `a == a` is not always `true` (think `NaN`)
- `a == c` is not always `false`
`input` and `expect` are parsed as `AST_BlockStatement` which does not support `AST_Directive` by default.
Emulate that by transforming preceding `AST_SimpleStatement`s of `AST_String` into `AST_Directive`.
`reduce_vars` enables substitution of variables but did not clone the value's `AST_Node`.
This confuses `collapse_vars` and result in invalid AST and subsequent crash.
fixes#1609
Liberal use of `Compressor.transform()` and `AST_Node.optimize()` presents an issue for look-up operations like `TreeWalker.in_boolean_context()` and `TreeWalker.parent()`.
This is an incremental fix such that `AST_Node.optimize()` would now contain the correct stack information when called correctly.
Self-referenced function has non-fixed values assigned to its parameters.
Let `unused` & `!keep_fnames` do the scanning, then apply `reduce_vars` only to unnamed functions.
fixes#1595
As patched on `harmony`, `statement()` is the only user of `embed_tokens()` with a missing error branch.
Updated test case and match up with `harmony` to facilitate future merging.
- one-use function call => IIFE should take `eval()` & `arguments` into account
- if unused parameter cannot be eliminated, replace it with `0`
fixes#1583
those were not optimised for `unused` before, which made it necessary for `reduce_vars` to have separate steps for `keep_fnames`
docs update by @kzc
closes#1577
Function expression can be assigned to a variable and be given a name. Ensure function name is the reduced variable before clearing it out.
fixes#1573fixes#1575
- omitting trailing semi-colon in do-while breaks non-browser parser, e.g. uglify-js 1.x
- trailing semi-colon only breaks IE8 if followed by `else` or `while`
- always use braces in do-while body to workaround 2nd case with no size loss in compression
fixes#1568
`AST_Label.references` get `.initialize()` to `[]` every time after `.clone()`
So walk down the tree to pick up the cloned `AST_LoopControl` pieces and put it back together.
`unsafe` turns undefined keyword into a variable of the same name if found, but that interferes with other related optimisations.
Keep track of such transformations to ensure zero information loss in the process.
Bookmarklet for instance implicitedly assumes a "completion value" without using `return`.
The `expression` option now supports such use cases.
Optimisations on IIFEs also enhanced.
fixes#354fixes#543fixes#625fixes#628fixes#640closes#1293
