Commit 3f608b1
tools: lint for function argument alignment
In function calls that span multiple lines, apply a custom lint rule to
enforce argument alignment.
With this rule, the following code will be flagged as an error by the
linter because the arguments on the second line start in a different
column than on the first line:
myFunction(a, b,
c, d);
The following code will not be flagged as an error by the linter:
myFunction(a, b,
c, d);
PR-URL: #6390
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Imran Iqbal <imran@imraniqbal.org>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Ryan Graham <r.m.graham@gmail.com>1 parent 6d1606e commit 3f608b1
2 files changed
Lines changed: 71 additions & 0 deletions
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -85,6 +85,7 @@ rules: | |||
| 85 | 85 | prefer-const: 2 | |
| 86 | 86 | ||
| 87 | 87 | # Custom rules in tools/eslint-rules | |
| 88 | + align-function-arguments: 2 | ||
| 88 | 89 | align-multiline-assignment: 2 | |
| 89 | 90 | assert-fail-single-argument: 2 | |
| 90 | 91 | new-with-error: [2, "Error", "RangeError", "TypeError", "SyntaxError", "ReferenceError"] | |
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -0,0 +1,70 @@ | |||
| 1 | + /** | ||
| 2 | + * @fileoverview Align arguments in multiline function calls | ||
| 3 | + * @author Rich Trott | ||
| 4 | + */ | ||
| 5 | + 'use strict'; | ||
| 6 | + | ||
| 7 | + //------------------------------------------------------------------------------ | ||
| 8 | + // Rule Definition | ||
| 9 | + //------------------------------------------------------------------------------ | ||
| 10 | + | ||
| 11 | + function checkArgumentAlignment(context, node) { | ||
| 12 | + | ||
| 13 | + function isNodeFirstInLine(node, byEndLocation) { | ||
| 14 | + const firstToken = byEndLocation === true ? context.getLastToken(node, 1) : | ||
| 15 | + context.getTokenBefore(node); | ||
| 16 | + const startLine = byEndLocation === true ? node.loc.end.line : | ||
| 17 | + node.loc.start.line; | ||
| 18 | + const endLine = firstToken ? firstToken.loc.end.line : -1; | ||
| 19 | + | ||
| 20 | + return startLine !== endLine; | ||
| 21 | + } | ||
| 22 | + | ||
| 23 | + if (node.arguments.length === 0) | ||
| 24 | + return; | ||
| 25 | + | ||
| 26 | + var msg = ''; | ||
| 27 | + const first = node.arguments[0]; | ||
| 28 | + var currentLine = first.loc.start.line; | ||
| 29 | + const firstColumn = first.loc.start.column; | ||
| 30 | + | ||
| 31 | + const ignoreTypes = [ | ||
| 32 | + 'ArrowFunctionExpression', | ||
| 33 | + 'CallExpression', | ||
| 34 | + 'FunctionExpression', | ||
| 35 | + 'ObjectExpression', | ||
| 36 | + 'TemplateLiteral' | ||
| 37 | + ]; | ||
| 38 | + | ||
| 39 | + const args = node.arguments; | ||
| 40 | + | ||
| 41 | + // For now, don't bother trying to validate potentially complicating things | ||
| 42 | + // like closures. Different people will have very different ideas and it's | ||
| 43 | + // probably best to implement configuration options. | ||
| 44 | + if (args.some((node) => { return ignoreTypes.indexOf(node.type) !== -1; })) { | ||
| 45 | + return; | ||
| 46 | + } | ||
| 47 | + | ||
| 48 | + if (!isNodeFirstInLine(node)) { | ||
| 49 | + return; | ||
| 50 | + } | ||
| 51 | + | ||
| 52 | + args.slice(1).forEach((argument) => { | ||
| 53 | + if (argument.loc.start.line === currentLine + 1) { | ||
| 54 | + if (argument.loc.start.column !== firstColumn) { | ||
| 55 | + msg = 'Function called with argument in column ' + | ||
| 56 | + `${argument.loc.start.column}, expected in ${firstColumn}`; | ||
| 57 | + } | ||
| 58 | + } | ||
| 59 | + currentLine = argument.loc.start.line; | ||
| 60 | + }); | ||
| 61 | + | ||
| 62 | + if (msg) | ||
| 63 | + context.report(node, msg); | ||
| 64 | + } | ||
| 65 | + | ||
| 66 | + module.exports = function(context) { | ||
| 67 | + return { | ||
| 68 | + 'CallExpression': (node) => checkArgumentAlignment(context, node) | ||
| 69 | + }; | ||
| 70 | + }; | ||
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