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Merge pull request #17096 from Microsoft/improve-return-type-parse-error

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Improve return type parse error
This commit is contained in:
Nathan Shively-Sanders 2017-07-12 07:18:23 -07:00 committed by GitHub
parent 38f6db52ac 1b1f257dbf
commit 50f39102aa
4 changed files with 134 additions and 41 deletions
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98
src/compiler/parser.ts
View file

@ -2,6 +2,15 @@
/// <reference path="scanner.ts"/>
namespace ts {
const enum SignatureFlags {
None = 0,
Yield = 1 << 0,
Await = 1 << 1,
Type = 1 << 2,
RequireCompleteParameterList = 1 << 3,
IgnoreMissingOpenBrace = 1 << 4,
}
let NodeConstructor: new (kind: SyntaxKind, pos: number, end: number) => Node;
let TokenConstructor: new (kind: SyntaxKind, pos: number, end: number) => Node;
let IdentifierConstructor: new (kind: SyntaxKind, pos: number, end: number) => Node;
@ -2218,15 +2227,12 @@ namespace ts {
function fillSignature(
returnToken: SyntaxKind.ColonToken | SyntaxKind.EqualsGreaterThanToken,
yieldContext: boolean,
awaitContext: boolean,
requireCompleteParameterList: boolean,
flags: SignatureFlags,
signature: SignatureDeclaration): void {
signature.typeParameters = parseTypeParameters();
signature.parameters = parseParameterList(flags);
const returnTokenRequired = returnToken === SyntaxKind.EqualsGreaterThanToken;
signature.typeParameters = parseTypeParameters();
signature.parameters = parseParameterList(yieldContext, awaitContext, requireCompleteParameterList);
if (returnTokenRequired) {
parseExpected(returnToken);
signature.type = parseTypeOrTypePredicate();
@ -2234,9 +2240,19 @@ namespace ts {
else if (parseOptional(returnToken)) {
signature.type = parseTypeOrTypePredicate();
}
else if (flags & SignatureFlags.Type) {
const start = scanner.getTokenPos();
const length = scanner.getTextPos() - start;
const backwardToken = parseOptional(returnToken === SyntaxKind.ColonToken ? SyntaxKind.EqualsGreaterThanToken : SyntaxKind.ColonToken);
if (backwardToken) {
// This is easy to get backward, especially in type contexts, so parse the type anyway
signature.type = parseTypeOrTypePredicate();
parseErrorAtPosition(start, length, Diagnostics._0_expected, tokenToString(returnToken));
}
}
}
function parseParameterList(yieldContext: boolean, awaitContext: boolean, requireCompleteParameterList: boolean) {
function parseParameterList(flags: SignatureFlags) {
// FormalParameters [Yield,Await]: (modified)
// [empty]
// FormalParameterList[?Yield,Await]
@ -2254,15 +2270,15 @@ namespace ts {
const savedYieldContext = inYieldContext();
const savedAwaitContext = inAwaitContext();
setYieldContext(yieldContext);
setAwaitContext(awaitContext);
setYieldContext(!!(flags & SignatureFlags.Yield));
setAwaitContext(!!(flags & SignatureFlags.Await));
const result = parseDelimitedList(ParsingContext.Parameters, parseParameter);
setYieldContext(savedYieldContext);
setAwaitContext(savedAwaitContext);
if (!parseExpected(SyntaxKind.CloseParenToken) && requireCompleteParameterList) {
if (!parseExpected(SyntaxKind.CloseParenToken) && (flags & SignatureFlags.RequireCompleteParameterList)) {
// Caller insisted that we had to end with a ) We didn't. So just return
// undefined here.
return undefined;
@ -2274,7 +2290,7 @@ namespace ts {
// We didn't even have an open paren. If the caller requires a complete parameter list,
// we definitely can't provide that. However, if they're ok with an incomplete one,
// then just return an empty set of parameters.
return requireCompleteParameterList ? undefined : createMissingList<ParameterDeclaration>();
return (flags & SignatureFlags.RequireCompleteParameterList) ? undefined : createMissingList<ParameterDeclaration>();
}
function parseTypeMemberSemicolon() {
@ -2293,7 +2309,7 @@ namespace ts {
if (kind === SyntaxKind.ConstructSignature) {
parseExpected(SyntaxKind.NewKeyword);
}
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ false, /*awaitContext*/ false, /*requireCompleteParameterList*/ false, node);
fillSignature(SyntaxKind.ColonToken, SignatureFlags.Type, node);
parseTypeMemberSemicolon();
return addJSDocComment(finishNode(node));
}
@ -2383,7 +2399,7 @@ namespace ts {
// Method signatures don't exist in expression contexts. So they have neither
// [Yield] nor [Await]
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ false, /*awaitContext*/ false, /*requireCompleteParameterList*/ false, method);
fillSignature(SyntaxKind.ColonToken, SignatureFlags.Type, method);
parseTypeMemberSemicolon();
return addJSDocComment(finishNode(method));
}
@ -2527,7 +2543,7 @@ namespace ts {
if (kind === SyntaxKind.ConstructorType) {
parseExpected(SyntaxKind.NewKeyword);
}
fillSignature(SyntaxKind.EqualsGreaterThanToken, /*yieldContext*/ false, /*awaitContext*/ false, /*requireCompleteParameterList*/ false, node);
fillSignature(SyntaxKind.EqualsGreaterThanToken, SignatureFlags.Type, node);
return finishNode(node);
}
@ -3254,7 +3270,7 @@ namespace ts {
function parseParenthesizedArrowFunctionExpressionHead(allowAmbiguity: boolean): ArrowFunction {
const node = <ArrowFunction>createNode(SyntaxKind.ArrowFunction);
node.modifiers = parseModifiersForArrowFunction();
const isAsync = !!(getModifierFlags(node) & ModifierFlags.Async);
const isAsync = (getModifierFlags(node) & ModifierFlags.Async) ? SignatureFlags.Await : SignatureFlags.None;
// Arrow functions are never generators.
//
@ -3263,7 +3279,7 @@ namespace ts {
// a => (b => c)
// And think that "(b =>" was actually a parenthesized arrow function with a missing
// close paren.
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ false, /*awaitContext*/ isAsync, /*requireCompleteParameterList*/ !allowAmbiguity, node);
fillSignature(SyntaxKind.ColonToken, isAsync | (allowAmbiguity ? SignatureFlags.None : SignatureFlags.RequireCompleteParameterList), node);
// If we couldn't get parameters, we definitely could not parse out an arrow function.
if (!node.parameters) {
@ -3288,7 +3304,7 @@ namespace ts {
function parseArrowFunctionExpressionBody(isAsync: boolean): Block | Expression {
if (token() === SyntaxKind.OpenBraceToken) {
return parseFunctionBlock(/*allowYield*/ false, /*allowAwait*/ isAsync, /*ignoreMissingOpenBrace*/ false);
return parseFunctionBlock(isAsync ? SignatureFlags.Await : SignatureFlags.None);
}
if (token() !== SyntaxKind.SemicolonToken &&
@ -3309,8 +3325,8 @@ namespace ts {
// try to recover better. If we don't do this, then the next close curly we see may end
// up preemptively closing the containing construct.
//
// Note: even when 'ignoreMissingOpenBrace' is passed as true, parseBody will still error.
return parseFunctionBlock(/*allowYield*/ false, /*allowAwait*/ isAsync, /*ignoreMissingOpenBrace*/ true);
// Note: even when 'IgnoreMissingOpenBrace' is passed, parseBody will still error.
return parseFunctionBlock(SignatureFlags.IgnoreMissingOpenBrace | (isAsync ? SignatureFlags.Await : SignatureFlags.None));
}
return isAsync
@ -4386,16 +4402,16 @@ namespace ts {
parseExpected(SyntaxKind.FunctionKeyword);
node.asteriskToken = parseOptionalToken(SyntaxKind.AsteriskToken);
const isGenerator = !!node.asteriskToken;
const isAsync = !!(getModifierFlags(node) & ModifierFlags.Async);
const isGenerator = node.asteriskToken ? SignatureFlags.Yield : SignatureFlags.None;
const isAsync = (getModifierFlags(node) & ModifierFlags.Async) ? SignatureFlags.Await : SignatureFlags.None;
node.name =
isGenerator && isAsync ? doInYieldAndAwaitContext(parseOptionalIdentifier) :
isGenerator ? doInYieldContext(parseOptionalIdentifier) :
isAsync ? doInAwaitContext(parseOptionalIdentifier) :
parseOptionalIdentifier();
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ isGenerator, /*awaitContext*/ isAsync, /*requireCompleteParameterList*/ false, node);
node.body = parseFunctionBlock(/*allowYield*/ isGenerator, /*allowAwait*/ isAsync, /*ignoreMissingOpenBrace*/ false);
fillSignature(SyntaxKind.ColonToken, isGenerator | isAsync, node);
node.body = parseFunctionBlock(isGenerator | isAsync);
if (saveDecoratorContext) {
setDecoratorContext(/*val*/ true);
@ -4444,12 +4460,12 @@ namespace ts {
return finishNode(node);
}
function parseFunctionBlock(allowYield: boolean, allowAwait: boolean, ignoreMissingOpenBrace: boolean, diagnosticMessage?: DiagnosticMessage): Block {
function parseFunctionBlock(flags: SignatureFlags, diagnosticMessage?: DiagnosticMessage): Block {
const savedYieldContext = inYieldContext();
setYieldContext(allowYield);
setYieldContext(!!(flags & SignatureFlags.Yield));
const savedAwaitContext = inAwaitContext();
setAwaitContext(allowAwait);
setAwaitContext(!!(flags & SignatureFlags.Await));
// We may be in a [Decorator] context when parsing a function expression or
// arrow function. The body of the function is not in [Decorator] context.
@ -4458,7 +4474,7 @@ namespace ts {
setDecoratorContext(/*val*/ false);
}
const block = parseBlock(ignoreMissingOpenBrace, diagnosticMessage);
const block = parseBlock(!!(flags & SignatureFlags.IgnoreMissingOpenBrace), diagnosticMessage);
if (saveDecoratorContext) {
setDecoratorContext(/*val*/ true);
@ -5005,13 +5021,13 @@ namespace ts {
return !scanner.hasPrecedingLineBreak() && (isIdentifier() || token() === SyntaxKind.StringLiteral);
}
function parseFunctionBlockOrSemicolon(isGenerator: boolean, isAsync: boolean, diagnosticMessage?: DiagnosticMessage): Block {
function parseFunctionBlockOrSemicolon(flags: SignatureFlags, diagnosticMessage?: DiagnosticMessage): Block {
if (token() !== SyntaxKind.OpenBraceToken && canParseSemicolon()) {
parseSemicolon();
return;
}
return parseFunctionBlock(isGenerator, isAsync, /*ignoreMissingOpenBrace*/ false, diagnosticMessage);
return parseFunctionBlock(flags, diagnosticMessage);
}
// DECLARATIONS
@ -5146,10 +5162,10 @@ namespace ts {
parseExpected(SyntaxKind.FunctionKeyword);
node.asteriskToken = parseOptionalToken(SyntaxKind.AsteriskToken);
node.name = hasModifier(node, ModifierFlags.Default) ? parseOptionalIdentifier() : parseIdentifier();
const isGenerator = !!node.asteriskToken;
const isAsync = hasModifier(node, ModifierFlags.Async);
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ isGenerator, /*awaitContext*/ isAsync, /*requireCompleteParameterList*/ false, node);
node.body = parseFunctionBlockOrSemicolon(isGenerator, isAsync, Diagnostics.or_expected);
const isGenerator = node.asteriskToken ? SignatureFlags.Yield : SignatureFlags.None;
const isAsync = hasModifier(node, ModifierFlags.Async) ? SignatureFlags.Await : SignatureFlags.None;
fillSignature(SyntaxKind.ColonToken, isGenerator | isAsync, node);
node.body = parseFunctionBlockOrSemicolon(isGenerator | isAsync, Diagnostics.or_expected);
return addJSDocComment(finishNode(node));
}
@ -5158,8 +5174,8 @@ namespace ts {
node.decorators = decorators;
node.modifiers = modifiers;
parseExpected(SyntaxKind.ConstructorKeyword);
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ false, /*awaitContext*/ false, /*requireCompleteParameterList*/ false, node);
node.body = parseFunctionBlockOrSemicolon(/*isGenerator*/ false, /*isAsync*/ false, Diagnostics.or_expected);
fillSignature(SyntaxKind.ColonToken, SignatureFlags.None, node);
node.body = parseFunctionBlockOrSemicolon(SignatureFlags.None, Diagnostics.or_expected);
return addJSDocComment(finishNode(node));
}
@ -5170,10 +5186,10 @@ namespace ts {
method.asteriskToken = asteriskToken;
method.name = name;
method.questionToken = questionToken;
const isGenerator = !!asteriskToken;
const isAsync = hasModifier(method, ModifierFlags.Async);
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ isGenerator, /*awaitContext*/ isAsync, /*requireCompleteParameterList*/ false, method);
method.body = parseFunctionBlockOrSemicolon(isGenerator, isAsync, diagnosticMessage);
const isGenerator = asteriskToken ? SignatureFlags.Yield : SignatureFlags.None;
const isAsync = hasModifier(method, ModifierFlags.Async) ? SignatureFlags.Await : SignatureFlags.None;
fillSignature(SyntaxKind.ColonToken, isGenerator | isAsync, method);
method.body = parseFunctionBlockOrSemicolon(isGenerator | isAsync, diagnosticMessage);
return addJSDocComment(finishNode(method));
}
@ -5226,8 +5242,8 @@ namespace ts {
node.decorators = decorators;
node.modifiers = modifiers;
node.name = parsePropertyName();
fillSignature(SyntaxKind.ColonToken, /*yieldContext*/ false, /*awaitContext*/ false, /*requireCompleteParameterList*/ false, node);
node.body = parseFunctionBlockOrSemicolon(/*isGenerator*/ false, /*isAsync*/ false);
fillSignature(SyntaxKind.ColonToken, SignatureFlags.None, node);
node.body = parseFunctionBlockOrSemicolon(SignatureFlags.None);
return addJSDocComment(finishNode(node));
}

37
tests/baselines/reference/parseErrorIncorrectReturnToken.errors.txt Normal file
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@ -0,0 +1,37 @@
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(2,17): error TS1005: ':' expected.
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(4,22): error TS1005: '=>' expected.
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(4,24): error TS2693: 'string' only refers to a type, but is being used as a value here.
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(9,18): error TS1005: '{' expected.
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(9,21): error TS2693: 'string' only refers to a type, but is being used as a value here.
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(9,28): error TS1005: ';' expected.
tests/cases/compiler/parseErrorIncorrectReturnToken.ts(12,1): error TS1128: Declaration or statement expected.
==== tests/cases/compiler/parseErrorIncorrectReturnToken.ts (7 errors) ====
type F1 = {
(n: number) => string; // should be : not =>
~~
!!! error TS1005: ':' expected.
}
type F2 = (n: number): string; // should be => not :
~
!!! error TS1005: '=>' expected.
~~~~~~
!!! error TS2693: 'string' only refers to a type, but is being used as a value here.
// doesn't work in non-type contexts, where the return type is optional
let f = (n: number) => string => n.toString();
let o = {
m(n: number) => string {
~~
!!! error TS1005: '{' expected.
~~~~~~
!!! error TS2693: 'string' only refers to a type, but is being used as a value here.
~
!!! error TS1005: ';' expected.
return n.toString();
}
};
~
!!! error TS1128: Declaration or statement expected.

27
tests/baselines/reference/parseErrorIncorrectReturnToken.js Normal file
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@ -0,0 +1,27 @@
//// [parseErrorIncorrectReturnToken.ts]
type F1 = {
(n: number) => string; // should be : not =>
}
type F2 = (n: number): string; // should be => not :
// doesn't work in non-type contexts, where the return type is optional
let f = (n: number) => string => n.toString();
let o = {
m(n: number) => string {
return n.toString();
}
};
//// [parseErrorIncorrectReturnToken.js]
string; // should be => not :
// doesn't work in non-type contexts, where the return type is optional
var f = function (n) { return function (string) { return n.toString(); }; };
var o = {
m: function (n) { }
};
string;
{
return n.toString();
}
;

13
tests/cases/compiler/parseErrorIncorrectReturnToken.ts Normal file
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@ -0,0 +1,13 @@
type F1 = {
(n: number) => string; // should be : not =>
}
type F2 = (n: number): string; // should be => not :
// doesn't work in non-type contexts, where the return type is optional
let f = (n: number) => string => n.toString();
let o = {
m(n: number) => string {
return n.toString();
}
};