ae3d28b5eb
* Implement constructor type guard * Fix code review issues for constructor type guard. - Do not limit constructor expression to only identifiers - Fix `assumeTrue` and operator no-narrow check - Use better way to check that identifier type is a function - Loosen restriction on what expr is left of ".constructor" - Update typeGuardConstructorClassAndNumber test to include else cases * Fix grammar & spacing in `narrowTypeByConstructor` * fix bad merge * switch (back?) to crlf * update baselines Co-authored-by: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
41 lines
889 B
TypeScript
41 lines
889 B
TypeScript
// @target: esnext
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// Narrow a union of primitive types
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let var1: string | number | boolean | any[] | symbol | bigint;
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if (var1.constructor === String) {
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var1; // string
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}
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if (var1.constructor === Number) {
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var1; // number
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}
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if (var1.constructor === Boolean) {
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var1; // boolean
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}
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if (var1.constructor === Array) {
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var1; // any[]
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}
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if (var1.constructor === Symbol) {
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var1; // symbol
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}
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if (var1.constructor === BigInt) {
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var1; // bigint
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}
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// Narrow a union of primitive object types
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let var2: String | Number | Boolean | Symbol | BigInt;
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if (var2.constructor === String) {
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var2; // String
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}
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if (var2.constructor === Number) {
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var2; // Number
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}
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if (var2.constructor === Boolean) {
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var2; // Boolean
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}
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if (var2.constructor === Symbol) {
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var2; // Symbol
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}
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if (var2.constructor === BigInt) {
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var2; // BigInt
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}
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