Add 'object-literal-contextual-type' rule#2581
Add 'object-literal-contextual-type' rule#2581andy-hanson wants to merge 4 commits intopalantir:masterfrom
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Rebased. |
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typescript has gotten better at handling objects like this. this rule is too aggressive (requiring too many changes and disables in existing source code).
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| public static ARGUMENT_DESCRIPTOR_BLOCK = { | ||
| public static ARGUMENT_DESCRIPTOR_BLOCK: {} = { |
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this isn't even correct. it has a much more advanced type than the empty object.
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{} is a correct type. Anything but null or undefined or void is assignable to {}.
| * limitations under the License. | ||
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| // tslint:disable object-literal-contextual-type |
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This is a comment, how does it break the API?
| interface I { x: number; } | ||
| function f(): I { | ||
| const res = { x: 0, y: 0 }; | ||
| return res; |
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this error can be avoided so many ways that don't require a rather aggressive lint rule...
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How would it be avoided in general? I don't believe typescript's behavior with respect to object literals has changed much in the past year.
Often people will think they're getting a contextual type when they really aren't, e.g. a result from a callback:
interface Options { foo?: number; bar?: number }
const arr: Options[] = [1, 2, 3].map(n => ({ foo: n, baa: n }));The error is fixed by changing to (n): Options, but I wouldn't want a lint rule to require all arrow functions to have explicit return types.
If there are better ways of avoiding this error I'd like to hear about them.
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Overview of change:
Added the
object-literal-contextual-typerule, which warns for an object literal with no contextual type (which may have unchecked excess properties).This branch is based on top of #2544 and will be rebased once that's in.
CHANGELOG.md entry:
[new-rule]
object-literal-contextual-type