16 lines
760 B
Plaintext
16 lines
760 B
Plaintext
==== tests/cases/conformance/types/typeRelationships/apparentType/apparentTypeSupertype.ts (1 errors) ====
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// subtype checks use the apparent type of the target type
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// S is a subtype of a type T, and T is a supertype of S, if one of the following is true, where S' denotes the apparent type (section 3.8.1) of S:
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class Base {
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x: string;
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}
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// is String (S) a subtype of U extends String (T)? Would only be true if we used the apparent type of U (T)
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class Derived<U extends String> extends Base { // error
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~~~~~~~
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!!! Class 'Derived<U>' incorrectly extends base class 'Base':
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!!! Types of property 'x' are incompatible:
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!!! Type 'U' is not assignable to type 'string'.
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x: U;
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} |