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Add exhaustiveness checking for try, catch, re-throw. #32952

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Add exhaustiveness checking for try, catch, re-throw. #32952

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22 changes: 14 additions & 8 deletions src/compiler/checker.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -23648,15 +23648,21 @@ namespace ts {
return eachTypeContainedIn(mapType(type, getRegularTypeOfLiteralType), switchTypes);
}

function functionHasImplicitReturn(func: FunctionLikeDeclaration) {
if (!(func.flags & NodeFlags.HasImplicitReturn)) {
return false;
}
function isTotalStatement(statement: Statement): boolean {
return statement.kind === SyntaxKind.SwitchStatement && isExhaustiveSwitchStatement(<SwitchStatement>statement) ||
statement.kind === SyntaxKind.TryStatement &&
((<TryStatement>statement).catchClause !== undefined) &&
some((<TryStatement>statement).catchClause!.block.statements, statement => statement.kind === SyntaxKind.ThrowStatement) &&
some((<TryStatement>statement).tryBlock.statements, isTotalStatement);
}

if (some((<Block>func.body).statements, statement => statement.kind === SyntaxKind.SwitchStatement && isExhaustiveSwitchStatement(<SwitchStatement>statement))) {
return false;
}
return true;
function functionHasImplicitReturn(func: FunctionLikeDeclaration) {
// A function has an implicit return if its body contains no total statements.
// A total statement explicitly returns or diverges, with the following cases recognized:
// (1) an exhaustive switch statement.
// (2) a try-catch statement where the catch clause always
// throws and the try block contains a total statement.
return !!(func.flags & NodeFlags.HasImplicitReturn) && !some((<Block>func.body).statements, isTotalStatement);
}

/** NOTE: Return value of `[]` means a different thing than `undefined`. `[]` means func returns `void`, `undefined` means it returns `never`. */
Expand Down
62 changes: 61 additions & 1 deletion tests/baselines/reference/exhaustiveSwitchImplicitReturn.errors.txt
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Original file line number Diff line number Diff line change
@@ -1,7 +1,8 @@
tests/cases/compiler/exhaustiveSwitchImplicitReturn.ts(35,32): error TS7030: Not all code paths return a value.
tests/cases/compiler/exhaustiveSwitchImplicitReturn.ts(82,28): error TS7030: Not all code paths return a value.


==== tests/cases/compiler/exhaustiveSwitchImplicitReturn.ts (1 errors) ====
==== tests/cases/compiler/exhaustiveSwitchImplicitReturn.ts (2 errors) ====
function foo1(bar: "a"): number {
switch(bar) {
case "a":
Expand Down Expand Up @@ -44,4 +45,63 @@ tests/cases/compiler/exhaustiveSwitchImplicitReturn.ts(35,32): error TS7030: Not
return 1;
}
}

// Repro from #32905.

enum Foo {
One,
Two,
Three
}

function test2(type: Foo): number {
try {
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
return 0;
}
} catch (e) {
throw new Error('some error')
}
}

function test3(type: Foo): number {
try {
console.log('some switch')
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
return 0;
}
} catch (e) {
console.log('some error')
throw new Error('some error')
}
}

function test4(type: Foo): number {
~~~~~~
!!! error TS7030: Not all code paths return a value.
try {
console.log('some switch')
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
0;
}
} catch (e) {
console.log('some error')
throw new Error('some error')
}
}

113 changes: 113 additions & 0 deletions tests/baselines/reference/exhaustiveSwitchImplicitReturn.js
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Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,63 @@ function foo5(bar: "a" | "b"): number {
return 1;
}
}

// Repro from #32905.

enum Foo {
One,
Two,
Three
}

function test2(type: Foo): number {
try {
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
return 0;
}
} catch (e) {
throw new Error('some error')
}
}

function test3(type: Foo): number {
try {
console.log('some switch')
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
return 0;
}
} catch (e) {
console.log('some error')
throw new Error('some error')
}
}

function test4(type: Foo): number {
try {
console.log('some switch')
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
0;
}
} catch (e) {
console.log('some error')
throw new Error('some error')
}
}


//// [exhaustiveSwitchImplicitReturn.js]
Expand Down Expand Up @@ -75,3 +132,59 @@ function foo5(bar) {
return 1;
}
}
// Repro from #32905.
var Foo;
(function (Foo) {
Foo[Foo["One"] = 0] = "One";
Foo[Foo["Two"] = 1] = "Two";
Foo[Foo["Three"] = 2] = "Three";
})(Foo || (Foo = {}));
function test2(type) {
try {
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
return 0;
}
}
catch (e) {
throw new Error('some error');
}
}
function test3(type) {
try {
console.log('some switch');
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
return 0;
}
}
catch (e) {
console.log('some error');
throw new Error('some error');
}
}
function test4(type) {
try {
console.log('some switch');
switch (type) {
case Foo.One:
return 0;
case Foo.Two:
return 0;
case Foo.Three:
0;
}
}
catch (e) {
console.log('some error');
throw new Error('some error');
}
}
143 changes: 143 additions & 0 deletions tests/baselines/reference/exhaustiveSwitchImplicitReturn.symbols
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Original file line number Diff line number Diff line change
Expand Up @@ -69,3 +69,146 @@ function foo5(bar: "a" | "b"): number {
}
}

// Repro from #32905.

enum Foo {
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))

One,
>One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))

Two,
>Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))

Three
>Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))
}

function test2(type: Foo): number {
>test2 : Symbol(test2, Decl(exhaustiveSwitchImplicitReturn.ts, 47, 1))
>type : Symbol(type, Decl(exhaustiveSwitchImplicitReturn.ts, 49, 15))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))

try {
switch (type) {
>type : Symbol(type, Decl(exhaustiveSwitchImplicitReturn.ts, 49, 15))

case Foo.One:
>Foo.One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))

return 0;
case Foo.Two:
>Foo.Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))

return 0;
case Foo.Three:
>Foo.Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))

return 0;
}
} catch (e) {
>e : Symbol(e, Decl(exhaustiveSwitchImplicitReturn.ts, 59, 13))

throw new Error('some error')
>Error : Symbol(Error, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
}
}

function test3(type: Foo): number {
>test3 : Symbol(test3, Decl(exhaustiveSwitchImplicitReturn.ts, 62, 1))
>type : Symbol(type, Decl(exhaustiveSwitchImplicitReturn.ts, 64, 15))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))

try {
console.log('some switch')
>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))

switch (type) {
>type : Symbol(type, Decl(exhaustiveSwitchImplicitReturn.ts, 64, 15))

case Foo.One:
>Foo.One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))

return 0;
case Foo.Two:
>Foo.Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))

return 0;
case Foo.Three:
>Foo.Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))

return 0;
}
} catch (e) {
>e : Symbol(e, Decl(exhaustiveSwitchImplicitReturn.ts, 75, 13))

console.log('some error')
>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))

throw new Error('some error')
>Error : Symbol(Error, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
}
}

function test4(type: Foo): number {
>test4 : Symbol(test4, Decl(exhaustiveSwitchImplicitReturn.ts, 79, 1))
>type : Symbol(type, Decl(exhaustiveSwitchImplicitReturn.ts, 81, 15))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))

try {
console.log('some switch')
>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))

switch (type) {
>type : Symbol(type, Decl(exhaustiveSwitchImplicitReturn.ts, 81, 15))

case Foo.One:
>Foo.One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>One : Symbol(Foo.One, Decl(exhaustiveSwitchImplicitReturn.ts, 43, 10))

return 0;
case Foo.Two:
>Foo.Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>Two : Symbol(Foo.Two, Decl(exhaustiveSwitchImplicitReturn.ts, 44, 8))

return 0;
case Foo.Three:
>Foo.Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))
>Foo : Symbol(Foo, Decl(exhaustiveSwitchImplicitReturn.ts, 39, 1))
>Three : Symbol(Foo.Three, Decl(exhaustiveSwitchImplicitReturn.ts, 45, 8))

0;
}
} catch (e) {
>e : Symbol(e, Decl(exhaustiveSwitchImplicitReturn.ts, 92, 13))

console.log('some error')
>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))

throw new Error('some error')
>Error : Symbol(Error, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --))
}
}

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