From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- .../eslint-plugin-mozilla/rules/use-isInstance.rst | 41 ++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 docs/code-quality/lint/linters/eslint-plugin-mozilla/rules/use-isInstance.rst (limited to 'docs/code-quality/lint/linters/eslint-plugin-mozilla/rules/use-isInstance.rst') diff --git a/docs/code-quality/lint/linters/eslint-plugin-mozilla/rules/use-isInstance.rst b/docs/code-quality/lint/linters/eslint-plugin-mozilla/rules/use-isInstance.rst new file mode 100644 index 0000000000..7ba4163228 --- /dev/null +++ b/docs/code-quality/lint/linters/eslint-plugin-mozilla/rules/use-isInstance.rst @@ -0,0 +1,41 @@ +use-isInstance +============== + +Prefer ``.isInstance()`` in chrome scripts over the standard ``instanceof`` +operator for DOM interfaces, since the latter will return false when the object +is created from a different context. + +These files are covered: + +- ``*.sys.mjs`` +- ``*.jsm`` +- ``*.xhtml`` with ``there.is.only.xul`` +- ``*.js`` with a heuristic + +Since there is no straightforward way to detect chrome scripts, currently the +linter assumes that any script including the following words are chrome +privileged. This of course may not be sufficient and is open for change: + +- ``ChromeUtils``, but not ``SpecialPowers.ChromeUtils`` +- ``BrowserTestUtils``, ``PlacesUtils`` +- ``document.createXULElement`` +- ``loader.lazyRequireGetter`` +- ``Services.foo``, but not ``SpecialPowers.Services.foo`` + +Examples of incorrect code for this rule: +----------------------------------------- + +.. code-block:: js + + node instanceof Node + text instanceof win.Text + target instanceof this.contentWindow.HTMLAudioElement + +Examples of correct code for this rule: +--------------------------------------- + +.. code-block:: js + + Node.isInstance(node) + win.Text.isInstance(text) + this.contentWindow.HTMLAudioElement.isInstance(target) -- cgit v1.2.3