Add arrow-return-shorthand rule
#1972
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| /* tslint:enable:object-literal-sort-keys */ | ||
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| public static FAILURE_STRING = | ||
| "Arrow function body may be converted just this expression, with no `{ return ... }`."; |
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How about This arrow function body can be simplified by omitting the curly braces and the keyword 'return' where the function body is underlined. Not sure that people will get what "this expression" means and that excluding { return ... } still includes the ...
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| // Invalid: | |||
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can you add a test case for returning an object literal?
| super.visitArrowFunction(node); | ||
| } | ||
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| private fix(arrowFunction: ts.FunctionLikeDeclaration, body: ts.Block, expr: ts.Expression): Lint.Fix | undefined { |
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rename to createArrowFunctionFix
| } | ||
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| class Walker extends Lint.RuleWalker { | ||
| public visitArrowFunction(node: ts.FunctionLikeDeclaration) { |
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You are only handling ts.ArrowFunctions here, so you can use it as your parameter's type. Same in the fix method below.
You can then omit the check for node.body && in the condition below, as it will always be defined.
| export class Rule extends Lint.Rules.AbstractRule { | ||
| /* tslint:disable:object-literal-sort-keys */ | ||
| public static metadata: Lint.IRuleMetadata = { | ||
| ruleName: "expression-valued-functions", |
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I don't really like this name. To me it's not clear what this rule does without looking at the description. I'm not a native speaker though.
I'd rename it to prefer-arrow-shorthand-return or similar ...
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yeah, I like prefer-arrow-shorthand-return as well
| public static metadata: Lint.IRuleMetadata = { | ||
| ruleName: "expression-valued-functions", | ||
| description: "Suggests to convert `() => { return x; }` to `() => x`.", | ||
| optionsDescription: "Not configurable.", |
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Can you add an option to exclude multiline arrow-functions.
Otherwise it would conflict with https://www.npmjs.com/package/vrsource-tslint-rules#multiline-arrow
It's not a core rule, but I like to use it to increase readability.
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I think this should skip multiline arrow functions by default; if you want to lint those too, you can add that as an option
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| function hasComments(start: number, end: number): boolean { | ||
| return !isAllWhitespace(text, start, end); |
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Can you use ts.get{Leading,Trailing}CommentRanges like in https://github.com/palantir/tslint/blob/master/src/rules/noEmptyRule.ts#L51-L52 instead of implementing it on your own?
If you feel like it, you could add a function to utils.js, e.g. hasCommentBetween(sourceFile, fromNode, toNode)
andy-hanson
changed the title
expression-valued-functions ruleprefer-arrow-shorthand-return rule
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| export class Rule extends Lint.Rules.AbstractRule { | ||
| /* tslint:disable:object-literal-sort-keys */ | ||
| public static metadata: Lint.IRuleMetadata = { |
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can you please add hasFix: true to the metadata?
| export class Rule extends Lint.Rules.AbstractRule { | ||
| /* tslint:disable:object-literal-sort-keys */ | ||
| public static metadata: Lint.IRuleMetadata = { | ||
| ruleName: "prefer-arrow-shorthand-return", |
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sorry for changing this up again -- I actually think we can simplify the name further and put "shorthand" at the end to be consistent with object-literal-shorthand. how about "arrow-return-shorthand"?
andy-hanson
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@andy-hanson thanks! |
nchen63
changed the title
prefer-arrow-shorthand-return rulearrow-shorthand-return rule
nchen63
changed the title
arrow-shorthand-return rulearrow-return-shorthand rule
This is missing in the rules documentation. |
PR checklist
What changes did you make?
Added the
expression-valued-functionsrule, which suggests to change() => { return x; }to() => x.