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ShuiRuTianShuiRuTian
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switch typeof any could be checked for unreachable (#39389)
* switch typeof any could be checked for unreachable * fix stupid error * support unknown * remvoe use less code. * fix spelling.
1 parent d897646 commit 5484687

11 files changed

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‎src/compiler/checker.ts

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@@ -131,6 +131,7 @@ namespace ts {
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UndefinedFacts = TypeofNEString | TypeofNENumber | TypeofNEBigInt | TypeofNEBoolean | TypeofNESymbol | TypeofNEObject | TypeofNEFunction | TypeofNEHostObject | EQUndefined | EQUndefinedOrNull | NENull | Falsy,
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NullFacts = TypeofEQObject | TypeofNEString | TypeofNENumber | TypeofNEBigInt | TypeofNEBoolean | TypeofNESymbol | TypeofNEFunction | TypeofNEHostObject | EQNull | EQUndefinedOrNull | NEUndefined | Falsy,
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EmptyObjectStrictFacts = All & ~(EQUndefined | EQNull | EQUndefinedOrNull),
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AllTypeofNE = TypeofNEString | TypeofNENumber | TypeofNEBigInt | TypeofNEBoolean | TypeofNESymbol | TypeofNEObject | TypeofNEFunction | NEUndefined,
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EmptyObjectFacts = All,
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}
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@@ -28273,6 +28274,10 @@ namespace ts {
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// notEqualFacts states that the type of the switched value is not equal to every type in the switch.
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const notEqualFacts = getFactsFromTypeofSwitch(0, 0, witnesses, /*hasDefault*/ true);
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const type = getBaseConstraintOfType(operandType) || operandType;
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// Take any/unknown as a special condition. Or maybe we could change `type` to a union containing all primitive types.
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if (type.flags & TypeFlags.AnyOrUnknown) {
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return (TypeFacts.AllTypeofNE & notEqualFacts) === TypeFacts.AllTypeofNE;
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}
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return !!(filterType(type, t => (getTypeFacts(t) & notEqualFacts) === notEqualFacts).flags & TypeFlags.Never);
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}
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const type = getTypeOfExpression(node.expression);

‎tests/baselines/reference/unreachableSwitchTypeofAny.errors.txt

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tests/cases/compiler/unreachable.ts(12,5): error TS7027: Unreachable code detected.
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==== tests/cases/compiler/unreachable.ts (1 errors) ====
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const unreachable = (x: any): number => {
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switch (typeof x) {
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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~~
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!!! error TS7027: Unreachable code detected.
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}

‎tests/baselines/reference/unreachableSwitchTypeofAny.js

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//// [unreachable.ts]
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const unreachable = (x: any): number => {
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switch (typeof x) {
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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}
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//// [unreachable.js]
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var unreachable = function (x) {
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switch (typeof x) {
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case 'string': return 0;
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case 'number': return 0;
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case 'bigint': return 0;
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case 'boolean': return 0;
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case 'symbol': return 0;
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case 'undefined': return 0;
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case 'object': return 0;
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case 'function': return 0;
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}
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x;
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};

‎tests/baselines/reference/unreachableSwitchTypeofAny.symbols

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=== tests/cases/compiler/unreachable.ts ===
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const unreachable = (x: any): number => {
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>unreachable : Symbol(unreachable, Decl(unreachable.ts, 0, 5))
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>x : Symbol(x, Decl(unreachable.ts, 0, 21))
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switch (typeof x) {
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>x : Symbol(x, Decl(unreachable.ts, 0, 21))
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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>x : Symbol(x, Decl(unreachable.ts, 0, 21))
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}

‎tests/baselines/reference/unreachableSwitchTypeofAny.types

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=== tests/cases/compiler/unreachable.ts ===
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const unreachable = (x: any): number => {
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>unreachable : (x: any) => number
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>(x: any): number => { switch (typeof x) { case 'string': return 0 case 'number': return 0 case 'bigint': return 0 case 'boolean': return 0 case 'symbol': return 0 case 'undefined': return 0 case 'object': return 0 case 'function': return 0 } x;} : (x: any) => number
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>x : any
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switch (typeof x) {
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>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
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>x : any
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case 'string': return 0
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>'string' : "string"
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>0 : 0
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case 'number': return 0
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>'number' : "number"
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>0 : 0
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case 'bigint': return 0
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>'bigint' : "bigint"
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>0 : 0
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case 'boolean': return 0
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>'boolean' : "boolean"
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>0 : 0
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case 'symbol': return 0
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>'symbol' : "symbol"
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>0 : 0
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case 'undefined': return 0
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>'undefined' : "undefined"
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>0 : 0
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case 'object': return 0
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>'object' : "object"
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>0 : 0
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case 'function': return 0
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>'function' : "function"
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>0 : 0
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}
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x;
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>x : any
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}

‎tests/baselines/reference/unreachableSwitchTypeofUnknown.errors.txt

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tests/cases/compiler/unreachable.ts(12,5): error TS7027: Unreachable code detected.
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==== tests/cases/compiler/unreachable.ts (1 errors) ====
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const unreachable = (x: unknown): number => {
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switch (typeof x) {
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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~~
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!!! error TS7027: Unreachable code detected.
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}

‎tests/baselines/reference/unreachableSwitchTypeofUnknown.js

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//// [unreachable.ts]
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const unreachable = (x: unknown): number => {
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switch (typeof x) {
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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}
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//// [unreachable.js]
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var unreachable = function (x) {
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switch (typeof x) {
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case 'string': return 0;
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case 'number': return 0;
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case 'bigint': return 0;
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case 'boolean': return 0;
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case 'symbol': return 0;
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case 'undefined': return 0;
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case 'object': return 0;
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case 'function': return 0;
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}
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x;
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};

‎tests/baselines/reference/unreachableSwitchTypeofUnknown.symbols

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=== tests/cases/compiler/unreachable.ts ===
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const unreachable = (x: unknown): number => {
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>unreachable : Symbol(unreachable, Decl(unreachable.ts, 0, 5))
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>x : Symbol(x, Decl(unreachable.ts, 0, 21))
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switch (typeof x) {
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>x : Symbol(x, Decl(unreachable.ts, 0, 21))
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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>x : Symbol(x, Decl(unreachable.ts, 0, 21))
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}

‎tests/baselines/reference/unreachableSwitchTypeofUnknown.types

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=== tests/cases/compiler/unreachable.ts ===
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const unreachable = (x: unknown): number => {
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>unreachable : (x: unknown) => number
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>(x: unknown): number => { switch (typeof x) { case 'string': return 0 case 'number': return 0 case 'bigint': return 0 case 'boolean': return 0 case 'symbol': return 0 case 'undefined': return 0 case 'object': return 0 case 'function': return 0 } x;} : (x: unknown) => number
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>x : unknown
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switch (typeof x) {
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>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
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>x : unknown
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case 'string': return 0
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>'string' : "string"
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>0 : 0
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case 'number': return 0
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>'number' : "number"
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>0 : 0
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case 'bigint': return 0
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>'bigint' : "bigint"
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>0 : 0
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case 'boolean': return 0
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>'boolean' : "boolean"
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>0 : 0
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case 'symbol': return 0
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>'symbol' : "symbol"
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>0 : 0
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case 'undefined': return 0
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>'undefined' : "undefined"
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>0 : 0
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case 'object': return 0
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>'object' : "object"
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>0 : 0
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case 'function': return 0
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>'function' : "function"
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>0 : 0
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}
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x;
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>x : unknown
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}

‎tests/cases/compiler/unreachableSwitchTypeofAny.ts

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// @Filename: unreachable.ts
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// @allowUnreachableCode: false
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const unreachable = (x: any): number => {
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switch (typeof x) {
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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}

‎tests/cases/compiler/unreachableSwitchTypeofUnknown.ts

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// @Filename: unreachable.ts
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// @allowUnreachableCode: false
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const unreachable = (x: unknown): number => {
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switch (typeof x) {
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case 'string': return 0
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case 'number': return 0
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case 'bigint': return 0
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case 'boolean': return 0
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case 'symbol': return 0
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case 'undefined': return 0
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case 'object': return 0
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case 'function': return 0
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}
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x;
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}

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