The remaining rules from the plugin's "Best Practices" category that the
recommended config leaves off, plus the two it only warns about, all of
which the code already complies with.
`regexp/prefer-regexp-test` is left off, since `unicorn/prefer-regexp-test`
already covers it.
`\d+\.?\d*` can split a run of digits in as many ways as it is long, so
it would backtrack polynomially if anything following it could reject.
The optional exponent can't, hence no bug today, but `\d+(?:\.\d*)?`
accepts the same numbers unambiguously.
It flags the regexes whose search is quadratic in the input length, like
the autolinker and XFA-path ones fixed recently.
The three existing offenders: `\s*` matched the CSS indentation but also
the line terminators that make `^` match with the `m` flag (the
preprocessed CSS is unchanged), `(\d+)` made every digit of a number a
candidate start position, and `/T.*$/` could fail on the `$` and
backtrack since `.` doesn't match a line terminator.
Follow-up to PR #21690: these tests check that pressing Home/End
correctly updates the last focused menu-item index, so that a following
ArrowUp/ArrowDown press doesn't move focus to an unexpected menu-item.
This fixes a bug when using the <kbd>Home</kbd> and <kbd>End</kbd> keyboard shortcuts to navigate through a `Menu` instance. These two buttons didn't update the `#lastIndex` field, which means that e.g. a following <kbd>ArrowDown</kbd> or <kbd>ArrowUp</kbd> press could make focus "jump" to an unexpected menu-item.
Also, the helper method reduces a little bit of code duplication in the event handlers.
Matching the name with a leading `.+` is quadratic in the length of
a component which doesn't end with a position, and every AcroForm
field name goes through this.
`toFixed(10)` switches to the exponential notation from 1e21 on, which isn't
valid PDF syntax, and removing the trailing zeros then dropped a digit of the
exponent: 1e30 was written "1e+3" and 1e100 "1e+1". Such a number, necessarily
an integer, is now written with all its digits.
The trailing zeros are removed with a backward scan, since `toFixed(10)` always
produces exactly 10 decimals. Below the 1e21 limit its output is at most 33
characters long, so the previous `$`-anchored regex wasn't a performance issue.
The local part and the domain labels were unbounded, making the
search quadratic in the length of a run of characters preceding
an "@": scanning the text of a single page could take seconds.
Compared to regular Objects there's a number of advantages to using Maps:
- They support proper iteration.
- They have a simple way to check for the existence of data.
- They have a simple/efficient way to check the number of elements.
If this functionality was added today, I cannot imagine that we'd choose an Object for this data.
In the Firefox PDF Viewer sending Maps to the scripting-implementation should be fine, since it uses the browser `Cu.cloneInto` functionality; see https://searchfox.org/firefox-main/source/toolkit/components/pdfjs/content/PdfSandbox.sys.mjs
However with QuickJS, used by the GENERIC viewer, all data needs to be stringified and Maps are converted into regular Objects (see also PR 21664). Hence the `objects` property, in the scripting-implementation, is converted back into a Map using the (renamed) `createMap` helper function.
In PR 12569 the `_actions` class-field was changed from an Object into a Map, with *most* of the code updated to reflect that.
However, in the `setAction` method it's still treated as an Object which means that any added script will simply be ignored. Most likely that part of the scripting-implementation isn't being used, since this code has been "wrong" for close to six years now.
Scanning to the end of the string for every "&" made the entity
resolution quadratic. Stopping at the next "&" also fixes a bare
ampersand swallowing the reference which follows it.
Finding the word to delete with a regex is quadratic in the value
length, so each "delete word backward" keystroke could take a long
time in a large field.
Searching for a name followed by ".pdf" is quadratic on a hash which
doesn't contain one, so locate the last ".pdf" first and then extend
it to the left.
Removing the trailing whitespace with a `$`-anchored regex is
quadratic in the length of the run, which a server controls.
The helper lives in network_utils.js, to be unit testable.
