Add a rule that prevents assignment from appearing in expression contexts. #442
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Creating this as a draft right now since it depends on the test fix in #441 to pass. cc @dylansturg |
| XCTAssertDiagnosed(.moveAssignmentToOwnStatement, line: 2, column: 10) | ||
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| func testReturnStatementWithAssignmentHasCommentMoved() { |
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What about if they're doing something silly like opening a multiline comment on the line with the return? I think the trailing trivia will get moved so that the return is sitting inside of the comment?
func foo() {
return a = b /* blargh
continues here */
}
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The trivia will never break within a block comment, so the entire comment (including its line break) will be a single trivia piece. We're also still using the hack workaround I wrote to preserve the legacy trivia behavior, so that comment would be in the leading trivia of the } token.
I did tweak this logic though to make sure it handles more cases around weird comments and added tests for those, PTAL.
…exts.
The main goal of this rule is to prevent "clever" code like this:
```
func foo() {
guard someCondition else { return someProperty = someValue }
// ...
}
```
That assignment can be easily misread as the Boolean `==` instead, and
most readers wouldn't expect side effects to appear in a `return`
statement like that. Just write it as two separate statements.
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The main goal of this rule is to prevent "clever" code like this:
That assignment can be easily misread as the Boolean
==instead, and most readers wouldn't expect side effects to appear in areturnstatement like that. Just write it as two separate statements.