feat(compiler): support unary operators for more accurate type checking (#37918)
Prior to this change, the unary + and - operators would be parsed as `x - 0` and `0 - x` respectively. The runtime semantics of these expressions are equivalent, however they may introduce inaccurate template type checking errors as the literal type is lost, for example: ```ts @Component({ template: `<button [disabled]="isAdjacent(-1)"></button>` }) export class Example { isAdjacent(direction: -1 | 1): boolean { return false; } } ``` would incorrectly report a type-check error: > error TS2345: Argument of type 'number' is not assignable to parameter of type '-1 | 1'. Additionally, the translated expression for the unary + operator would be considered as arithmetic expression with an incompatible left-hand side: > error TS2362: The left-hand side of an arithmetic operation must be of type 'any', 'number', 'bigint' or an enum type. To resolve this issues, the implicit transformation should be avoided. This commit adds a new unary AST node to represent these expressions, allowing for more accurate type-checking. Fixes #20845 Fixes #36178 PR Close #37918
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@ -102,6 +102,8 @@ describe('expression diagnostics', () => {
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it('should reject *ngIf of misspelled identifier in PrefixNot node',
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() =>
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reject('<div *ngIf="people && !persson"></div>', 'Identifier \'persson\' is not defined'));
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it('should reject misspelled field in unary operator expression',
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() => reject('{{ +persson }}', `Identifier 'persson' is not defined`));
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it('should accept an *ngFor', () => accept(`
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<div *ngFor="let p of people">
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{{p.name.first}} {{p.name.last}}
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