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Fix missed errors in switch when using union of literal and non-literal types (#38686) #51373

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Merged
merged 2 commits into from
Dec 6, 2022
Merged

Fix missed errors in switch when using union of literal and non-literal types (#38686) #51373

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39137f9
Fix missed errors in switch when using union of literal and non-liter…
ericbf Nov 15, 2022
95ff120
Fix lint (whitespace) issue in checker.ts by running lint with fix flag.
ericbf Nov 15, 2022
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15 changes: 5 additions & 10 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -40048,7 +40048,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
let hasDuplicateDefaultClause = false;

const expressionType = checkExpression(node.expression);
const expressionIsLiteral = isLiteralType(expressionType);

forEach(node.caseBlock.clauses, clause => {
// Grammar check for duplicate default clauses, skip if we already report duplicate default clause
if (clause.kind === SyntaxKind.DefaultClause && !hasDuplicateDefaultClause) {
Expand All @@ -40074,16 +40074,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
// TypeScript 1.0 spec (April 2014): 5.9
// In a 'switch' statement, each 'case' expression must be of a type that is comparable
// to or from the type of the 'switch' expression.
let caseType = checkExpression(clause.expression);
const caseIsLiteral = isLiteralType(caseType);
let comparedExpressionType = expressionType;
if (!caseIsLiteral || !expressionIsLiteral) {
caseType = caseIsLiteral ? getBaseTypeOfLiteralType(caseType) : caseType;
comparedExpressionType = getBaseTypeOfLiteralType(expressionType);
}
if (!isTypeEqualityComparableTo(comparedExpressionType, caseType)) {
const caseType = checkExpression(clause.expression);

if (!isTypeEqualityComparableTo(expressionType, caseType)) {
// expressionType is not comparable to caseType, try the reversed check and report errors if it fails
checkTypeComparableTo(caseType, comparedExpressionType, clause.expression, /*headMessage*/ undefined);
checkTypeComparableTo(caseType, expressionType, clause.expression, /*headMessage*/ undefined);
}
};
}
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4 changes: 2 additions & 2 deletions tests/baselines/reference/switchAssignmentCompat.errors.txt
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@@ -1,4 +1,4 @@
tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type '0'.


==== tests/cases/compiler/switchAssignmentCompat.ts (1 errors) ====
Expand All @@ -7,6 +7,6 @@ tests/cases/compiler/switchAssignmentCompat.ts(4,10): error TS2678: Type 'typeof
switch (0) {
case Foo: break; // Error expected
~~~
!!! error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
!!! error TS2678: Type 'typeof Foo' is not comparable to type '0'.
}

8 changes: 4 additions & 4 deletions tests/baselines/reference/switchCaseCircularRefeference.errors.txt
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@@ -1,5 +1,5 @@
tests/cases/compiler/switchCaseCircularRefeference.ts(5,10): error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type 'string'.
Type '{ a: "C"; e: any; }' is not comparable to type 'string'.
tests/cases/compiler/switchCaseCircularRefeference.ts(5,10): error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
Type '{ a: "C"; e: any; }' is not comparable to type '"A" | "C"'.


==== tests/cases/compiler/switchCaseCircularRefeference.ts (1 errors) ====
Expand All @@ -9,8 +9,8 @@ tests/cases/compiler/switchCaseCircularRefeference.ts(5,10): error TS2678: Type
switch (x.a) {
case x:
~
!!! error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type 'string'.
!!! error TS2678: Type '{ a: "C"; e: any; }' is not comparable to type 'string'.
!!! error TS2678: Type '{ a: "A"; b: any; } | { a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
!!! error TS2678: Type '{ a: "C"; e: any; }' is not comparable to type '"A" | "C"'.
break;
}
}
23 changes: 20 additions & 3 deletions tests/baselines/reference/switchCasesExpressionTypeMismatch.errors.txt
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@@ -1,16 +1,18 @@
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(4,10): error TS2678: Type 'typeof Foo' is not comparable to type '0'.
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(5,10): error TS2678: Type '"sss"' is not comparable to type '0'.
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(6,10): error TS2678: Type '123' is not comparable to type '0'.
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2678: Type 'true' is not comparable to type '0'.
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(16,10): error TS2678: Type 'true' is not comparable to type 'number | "hello"'.
tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(18,10): error TS2678: Type '"world"' is not comparable to type 'number | "hello"'.


==== tests/cases/compiler/switchCasesExpressionTypeMismatch.ts (4 errors) ====
==== tests/cases/compiler/switchCasesExpressionTypeMismatch.ts (6 errors) ====
class Foo { }

switch (0) {
case Foo: break; // Error
~~~
!!! error TS2678: Type 'typeof Foo' is not comparable to type 'number'.
!!! error TS2678: Type 'typeof Foo' is not comparable to type '0'.
case "sss": break; // Error
~~~~~
!!! error TS2678: Type '"sss"' is not comparable to type '0'.
Expand All @@ -22,6 +24,21 @@ tests/cases/compiler/switchCasesExpressionTypeMismatch.ts(7,10): error TS2678: T
!!! error TS2678: Type 'true' is not comparable to type '0'.
}

declare var q: string
declare var r: number | "hello"

switch (r) {
case q: break
case 42: break
case true: break // Error
~~~~
!!! error TS2678: Type 'true' is not comparable to type 'number | "hello"'.
case "hello": break
case "world": break // Error
~~~~~~~
!!! error TS2678: Type '"world"' is not comparable to type 'number | "hello"'.
}

var s: any = 0;

// No error for all
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18 changes: 18 additions & 0 deletions tests/baselines/reference/switchCasesExpressionTypeMismatch.js
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Expand Up @@ -8,6 +8,17 @@ switch (0) {
case true: break; // Error
}

declare var q: string
declare var r: number | "hello"

switch (r) {
case q: break
case 42: break
case true: break // Error
case "hello": break
case "world": break // Error
}

var s: any = 0;

// No error for all
Expand All @@ -31,6 +42,13 @@ switch (0) {
case 123: break; // Error
case true: break; // Error
}
switch (r) {
case q: break;
case 42: break;
case true: break; // Error
case "hello": break;
case "world": break; // Error
}
var s = 0;
// No error for all
switch (s) {
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22 changes: 20 additions & 2 deletions tests/baselines/reference/switchCasesExpressionTypeMismatch.symbols
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Expand Up @@ -11,12 +11,30 @@ switch (0) {
case true: break; // Error
}

declare var q: string
>q : Symbol(q, Decl(switchCasesExpressionTypeMismatch.ts, 9, 11))

declare var r: number | "hello"
>r : Symbol(r, Decl(switchCasesExpressionTypeMismatch.ts, 10, 11))

switch (r) {
>r : Symbol(r, Decl(switchCasesExpressionTypeMismatch.ts, 10, 11))

case q: break
>q : Symbol(q, Decl(switchCasesExpressionTypeMismatch.ts, 9, 11))

case 42: break
case true: break // Error
case "hello": break
case "world": break // Error
}

var s: any = 0;
>s : Symbol(s, Decl(switchCasesExpressionTypeMismatch.ts, 9, 3))
>s : Symbol(s, Decl(switchCasesExpressionTypeMismatch.ts, 20, 3))

// No error for all
switch (s) {
>s : Symbol(s, Decl(switchCasesExpressionTypeMismatch.ts, 9, 3))
>s : Symbol(s, Decl(switchCasesExpressionTypeMismatch.ts, 20, 3))

case Foo: break;
>Foo : Symbol(Foo, Decl(switchCasesExpressionTypeMismatch.ts, 0, 0))
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25 changes: 25 additions & 0 deletions tests/baselines/reference/switchCasesExpressionTypeMismatch.types
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Expand Up @@ -18,6 +18,31 @@ switch (0) {
>true : true
}

declare var q: string
>q : string

declare var r: number | "hello"
>r : number | "hello"

switch (r) {
>r : number | "hello"

case q: break
>q : string

case 42: break
>42 : 42

case true: break // Error
>true : true

case "hello": break
>"hello" : "hello"

case "world": break // Error
>"world" : "world"
}

var s: any = 0;
>s : any
>0 : 0
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11 changes: 11 additions & 0 deletions tests/cases/compiler/switchCasesExpressionTypeMismatch.ts
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Expand Up @@ -7,6 +7,17 @@ switch (0) {
case true: break; // Error
}

declare var q: string
declare var r: number | "hello"

switch (r) {
case q: break
case 42: break
case true: break // Error
case "hello": break
case "world": break // Error
}

var s: any = 0;

// No error for all
Expand Down