This repository has been archived by the owner on Mar 25, 2021. It is now read-only.
Add strict-type-predicates rule
#2046
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
ajafff
reviewed
Jan 16, 2017
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [F] | ||
|
|
||
| get<number | undefined>() === undefined; | ||
| get<string | undefined>() == null; |
There was a problem hiding this comment.
Could this rule also check for non strict comparisons to null or undefined if only one of them is possible?
Example:
get<string|undefined>() == null;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [use === undefined instead]
get<string|undefined|null>() == null; // still allowed| get<string | undefined>() == null; | ||
| get<string | null>() == undefined; | ||
| get<string | null>() == null; | ||
| get<string | undefined>() == undefined; |
There was a problem hiding this comment.
here the rule could suggest to use strict equality comparison
| get<string | undefined>() == null; | ||
| get<string | null>() == undefined; | ||
| get<string | null>() == null; | ||
| get<string | undefined>() == undefined; |
There was a problem hiding this comment.
Please add a test for the following:
get<null|undefined> == null;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [T]
get<null|undefined> != undefined;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [F]
nchen63
reviewed
Jan 16, 2017
| @@ -0,0 +1,210 @@ | |||
| /** | |||
| * @license | |||
| * Copyright 2016 Palantir Technologies, Inc. | |||
| @@ -178,6 +178,11 @@ export function isTypeFlagSet(type: ts.Type, flagToCheck: ts.TypeFlags): boolean | |||
| /* tslint:enable:no-bitwise */ | |||
| } | |||
|
|
|||
| /** Type predicate to test for a union type. */ | |||
| export function isUnionType(type: ts.Type): type is ts.UnionType { | |||
There was a problem hiding this comment.
utils shouldn't be cluttered with wrappers for isTypeFlagSet
andy-hanson
force-pushed
the
strict_type_predicates
branch
from
2c491e0
to
c263f8c
Compare
|
Would this rule make |
|
@andy-hanson if it catches typos like |
|
sorry, can you merge with master? |
andy-hanson
force-pushed
the
strict_type_predicates
branch
from
b78a139
to
c57cbf4
Compare
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
PR checklist
What changes did you make?
Added the
strict-type-predicatesrule, which warns fortypeof x === "string"wherexis always (or never) a string, and forx === undefinedwherexis always (or never)undefined.Is there anything you'd like reviewers to focus on?
Can't do
instanceofchecks yet as the type checker does not expose assignability checks. If it did, thegetTypePredicateForKindfunction could be removed.