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Fix switch statement control flow logic #29563

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Merged
merged 5 commits into from
Jan 24, 2019
Merged

Fix switch statement control flow logic #29563

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9844436
Match control flow logic for switch statements to conditional express…
ahejlsberg Jan 24, 2019
83f7f4d
Add regression test
ahejlsberg Jan 24, 2019
48cad77
Accept new baselines
ahejlsberg Jan 24, 2019
500c472
Add additional repro
ahejlsberg Jan 24, 2019
936ee9b
Accept new baselines
ahejlsberg Jan 24, 2019
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6 changes: 3 additions & 3 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -15780,9 +15780,6 @@ namespace ts {

function getTypeAtSwitchClause(flow: FlowSwitchClause): FlowType {
const expr = flow.switchStatement.expression;
if (containsMatchingReferenceDiscriminant(reference, expr)) {
return declaredType;
}
const flowType = getTypeAtFlowNode(flow.antecedent);
let type = getTypeFromFlowType(flowType);
if (isMatchingReference(reference, expr)) {
Expand All @@ -15797,6 +15794,9 @@ namespace ts {
else if (expr.kind === SyntaxKind.TypeOfExpression && isMatchingReference(reference, (expr as TypeOfExpression).expression)) {
type = narrowBySwitchOnTypeOf(type, flow.switchStatement, flow.clauseStart, flow.clauseEnd);
}
else if (containsMatchingReferenceDiscriminant(reference, expr)) {
type = declaredType;
}
return createFlowType(type, isIncomplete(flowType));
}

Expand Down
54 changes: 54 additions & 0 deletions tests/baselines/reference/discriminantPropertyCheck.errors.txt
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Expand Up @@ -128,4 +128,58 @@ tests/cases/compiler/discriminantPropertyCheck.ts(65,9): error TS2532: Object is
u.a && u.b && f(u.a, u.b);

u.b && u.a && f(u.a, u.b);

// Repro from #29012

type Additive = '+' | '-';
type Multiplicative = '*' | '/';

interface AdditiveObj {
key: Additive
}

interface MultiplicativeObj {
key: Multiplicative
}

type Obj = AdditiveObj | MultiplicativeObj

export function foo(obj: Obj) {
switch (obj.key) {
case '+': {
onlyPlus(obj.key);
return;
}
}
}

function onlyPlus(arg: '+') {
return arg;
}

// Repro from #29496

declare function never(value: never): never;

const enum BarEnum {
bar1 = 1,
bar2 = 2,
}

type UnionOfBar = TypeBar1 | TypeBar2;
type TypeBar1 = { type: BarEnum.bar1 };
type TypeBar2 = { type: BarEnum.bar2 };

function func3(value: Partial<UnionOfBar>) {
if (value.type !== undefined) {
switch (value.type) {
case BarEnum.bar1:
break;
case BarEnum.bar2:
break;
default:
never(value.type);
}
}
}

80 changes: 80 additions & 0 deletions tests/baselines/reference/discriminantPropertyCheck.js
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Expand Up @@ -120,9 +120,65 @@ const u: U = {} as any;
u.a && u.b && f(u.a, u.b);

u.b && u.a && f(u.a, u.b);

// Repro from #29012

type Additive = '+' | '-';
type Multiplicative = '*' | '/';

interface AdditiveObj {
key: Additive
}

interface MultiplicativeObj {
key: Multiplicative
}

type Obj = AdditiveObj | MultiplicativeObj

export function foo(obj: Obj) {
switch (obj.key) {
case '+': {
onlyPlus(obj.key);
return;
}
}
}

function onlyPlus(arg: '+') {
return arg;
}

// Repro from #29496

declare function never(value: never): never;

const enum BarEnum {
bar1 = 1,
bar2 = 2,
}

type UnionOfBar = TypeBar1 | TypeBar2;
type TypeBar1 = { type: BarEnum.bar1 };
type TypeBar2 = { type: BarEnum.bar2 };

function func3(value: Partial<UnionOfBar>) {
if (value.type !== undefined) {
switch (value.type) {
case BarEnum.bar1:
break;
case BarEnum.bar2:
break;
default:
never(value.type);
}
}
}


//// [discriminantPropertyCheck.js]
"use strict";
exports.__esModule = true;
function goo1(x) {
if (x.kind === "A" && x.foo !== undefined) {
x.foo.length;
Expand Down Expand Up @@ -188,3 +244,27 @@ var f = function (_a, _b) { };
var u = {};
u.a && u.b && f(u.a, u.b);
u.b && u.a && f(u.a, u.b);
function foo(obj) {
switch (obj.key) {
case '+': {
onlyPlus(obj.key);
return;
}
}
}
exports.foo = foo;
function onlyPlus(arg) {
return arg;
}
function func3(value) {
if (value.type !== undefined) {
switch (value.type) {
case 1 /* bar1 */:
break;
case 2 /* bar2 */:
break;
default:
never(value.type);
}
}
}
131 changes: 131 additions & 0 deletions tests/baselines/reference/discriminantPropertyCheck.symbols
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Original file line number Diff line number Diff line change
Expand Up @@ -377,3 +377,134 @@ u.b && u.a && f(u.a, u.b);
>u : Symbol(u, Decl(discriminantPropertyCheck.ts, 116, 5))
>b : Symbol(b, Decl(discriminantPropertyCheck.ts, 105, 13), Decl(discriminantPropertyCheck.ts, 110, 12))

// Repro from #29012

type Additive = '+' | '-';
>Additive : Symbol(Additive, Decl(discriminantPropertyCheck.ts, 120, 26))

type Multiplicative = '*' | '/';
>Multiplicative : Symbol(Multiplicative, Decl(discriminantPropertyCheck.ts, 124, 26))

interface AdditiveObj {
>AdditiveObj : Symbol(AdditiveObj, Decl(discriminantPropertyCheck.ts, 125, 32))

key: Additive
>key : Symbol(AdditiveObj.key, Decl(discriminantPropertyCheck.ts, 127, 23))
>Additive : Symbol(Additive, Decl(discriminantPropertyCheck.ts, 120, 26))
}

interface MultiplicativeObj {
>MultiplicativeObj : Symbol(MultiplicativeObj, Decl(discriminantPropertyCheck.ts, 129, 1))

key: Multiplicative
>key : Symbol(MultiplicativeObj.key, Decl(discriminantPropertyCheck.ts, 131, 29))
>Multiplicative : Symbol(Multiplicative, Decl(discriminantPropertyCheck.ts, 124, 26))
}

type Obj = AdditiveObj | MultiplicativeObj
>Obj : Symbol(Obj, Decl(discriminantPropertyCheck.ts, 133, 1))
>AdditiveObj : Symbol(AdditiveObj, Decl(discriminantPropertyCheck.ts, 125, 32))
>MultiplicativeObj : Symbol(MultiplicativeObj, Decl(discriminantPropertyCheck.ts, 129, 1))

export function foo(obj: Obj) {
>foo : Symbol(foo, Decl(discriminantPropertyCheck.ts, 135, 42))
>obj : Symbol(obj, Decl(discriminantPropertyCheck.ts, 137, 20))
>Obj : Symbol(Obj, Decl(discriminantPropertyCheck.ts, 133, 1))

switch (obj.key) {
>obj.key : Symbol(key, Decl(discriminantPropertyCheck.ts, 127, 23), Decl(discriminantPropertyCheck.ts, 131, 29))
>obj : Symbol(obj, Decl(discriminantPropertyCheck.ts, 137, 20))
>key : Symbol(key, Decl(discriminantPropertyCheck.ts, 127, 23), Decl(discriminantPropertyCheck.ts, 131, 29))

case '+': {
onlyPlus(obj.key);
>onlyPlus : Symbol(onlyPlus, Decl(discriminantPropertyCheck.ts, 144, 1))
>obj.key : Symbol(AdditiveObj.key, Decl(discriminantPropertyCheck.ts, 127, 23))
>obj : Symbol(obj, Decl(discriminantPropertyCheck.ts, 137, 20))
>key : Symbol(AdditiveObj.key, Decl(discriminantPropertyCheck.ts, 127, 23))

return;
}
}
}

function onlyPlus(arg: '+') {
>onlyPlus : Symbol(onlyPlus, Decl(discriminantPropertyCheck.ts, 144, 1))
>arg : Symbol(arg, Decl(discriminantPropertyCheck.ts, 146, 18))

return arg;
>arg : Symbol(arg, Decl(discriminantPropertyCheck.ts, 146, 18))
}

// Repro from #29496

declare function never(value: never): never;
>never : Symbol(never, Decl(discriminantPropertyCheck.ts, 148, 1))
>value : Symbol(value, Decl(discriminantPropertyCheck.ts, 152, 23))

const enum BarEnum {
>BarEnum : Symbol(BarEnum, Decl(discriminantPropertyCheck.ts, 152, 44))

bar1 = 1,
>bar1 : Symbol(BarEnum.bar1, Decl(discriminantPropertyCheck.ts, 154, 20))

bar2 = 2,
>bar2 : Symbol(BarEnum.bar2, Decl(discriminantPropertyCheck.ts, 155, 13))
}

type UnionOfBar = TypeBar1 | TypeBar2;
>UnionOfBar : Symbol(UnionOfBar, Decl(discriminantPropertyCheck.ts, 157, 1))
>TypeBar1 : Symbol(TypeBar1, Decl(discriminantPropertyCheck.ts, 159, 38))
>TypeBar2 : Symbol(TypeBar2, Decl(discriminantPropertyCheck.ts, 160, 39))

type TypeBar1 = { type: BarEnum.bar1 };
>TypeBar1 : Symbol(TypeBar1, Decl(discriminantPropertyCheck.ts, 159, 38))
>type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17))
>BarEnum : Symbol(BarEnum, Decl(discriminantPropertyCheck.ts, 152, 44))
>bar1 : Symbol(BarEnum.bar1, Decl(discriminantPropertyCheck.ts, 154, 20))

type TypeBar2 = { type: BarEnum.bar2 };
>TypeBar2 : Symbol(TypeBar2, Decl(discriminantPropertyCheck.ts, 160, 39))
>type : Symbol(type, Decl(discriminantPropertyCheck.ts, 161, 17))
>BarEnum : Symbol(BarEnum, Decl(discriminantPropertyCheck.ts, 152, 44))
>bar2 : Symbol(BarEnum.bar2, Decl(discriminantPropertyCheck.ts, 155, 13))

function func3(value: Partial<UnionOfBar>) {
>func3 : Symbol(func3, Decl(discriminantPropertyCheck.ts, 161, 39))
>value : Symbol(value, Decl(discriminantPropertyCheck.ts, 163, 15))
>Partial : Symbol(Partial, Decl(lib.es5.d.ts, --, --))
>UnionOfBar : Symbol(UnionOfBar, Decl(discriminantPropertyCheck.ts, 157, 1))

if (value.type !== undefined) {
>value.type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17), Decl(discriminantPropertyCheck.ts, 161, 17))
>value : Symbol(value, Decl(discriminantPropertyCheck.ts, 163, 15))
>type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17), Decl(discriminantPropertyCheck.ts, 161, 17))
>undefined : Symbol(undefined)

switch (value.type) {
>value.type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17), Decl(discriminantPropertyCheck.ts, 161, 17))
>value : Symbol(value, Decl(discriminantPropertyCheck.ts, 163, 15))
>type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17), Decl(discriminantPropertyCheck.ts, 161, 17))

case BarEnum.bar1:
>BarEnum.bar1 : Symbol(BarEnum.bar1, Decl(discriminantPropertyCheck.ts, 154, 20))
>BarEnum : Symbol(BarEnum, Decl(discriminantPropertyCheck.ts, 152, 44))
>bar1 : Symbol(BarEnum.bar1, Decl(discriminantPropertyCheck.ts, 154, 20))

break;
case BarEnum.bar2:
>BarEnum.bar2 : Symbol(BarEnum.bar2, Decl(discriminantPropertyCheck.ts, 155, 13))
>BarEnum : Symbol(BarEnum, Decl(discriminantPropertyCheck.ts, 152, 44))
>bar2 : Symbol(BarEnum.bar2, Decl(discriminantPropertyCheck.ts, 155, 13))

break;
default:
never(value.type);
>never : Symbol(never, Decl(discriminantPropertyCheck.ts, 148, 1))
>value.type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17), Decl(discriminantPropertyCheck.ts, 161, 17))
>value : Symbol(value, Decl(discriminantPropertyCheck.ts, 163, 15))
>type : Symbol(type, Decl(discriminantPropertyCheck.ts, 160, 17), Decl(discriminantPropertyCheck.ts, 161, 17))
}
}
}

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