mirror of
https://github.com/Sevichecc/Urara-Blog.git
synced 2025-05-05 04:09:31 +08:00
246 lines
No EOL
12 KiB
Text
246 lines
No EOL
12 KiB
Text
"use strict";
|
|
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
|
|
if (k2 === undefined) k2 = k;
|
|
var desc = Object.getOwnPropertyDescriptor(m, k);
|
|
if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
|
|
desc = { enumerable: true, get: function() { return m[k]; } };
|
|
}
|
|
Object.defineProperty(o, k2, desc);
|
|
}) : (function(o, m, k, k2) {
|
|
if (k2 === undefined) k2 = k;
|
|
o[k2] = m[k];
|
|
}));
|
|
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
|
|
Object.defineProperty(o, "default", { enumerable: true, value: v });
|
|
}) : function(o, v) {
|
|
o["default"] = v;
|
|
});
|
|
var __importStar = (this && this.__importStar) || function (mod) {
|
|
if (mod && mod.__esModule) return mod;
|
|
var result = {};
|
|
if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
|
|
__setModuleDefault(result, mod);
|
|
return result;
|
|
};
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
const utils_1 = require("@typescript-eslint/utils");
|
|
const tsutils_1 = require("tsutils");
|
|
const ts = __importStar(require("typescript"));
|
|
const util = __importStar(require("../util"));
|
|
exports.default = util.createRule({
|
|
name: 'no-unnecessary-type-assertion',
|
|
meta: {
|
|
docs: {
|
|
description: 'Disallow type assertions that do not change the type of an expression',
|
|
recommended: 'error',
|
|
requiresTypeChecking: true,
|
|
},
|
|
fixable: 'code',
|
|
messages: {
|
|
unnecessaryAssertion: 'This assertion is unnecessary since it does not change the type of the expression.',
|
|
contextuallyUnnecessary: 'This assertion is unnecessary since the receiver accepts the original type of the expression.',
|
|
},
|
|
schema: [
|
|
{
|
|
type: 'object',
|
|
properties: {
|
|
typesToIgnore: {
|
|
type: 'array',
|
|
items: {
|
|
type: 'string',
|
|
},
|
|
},
|
|
},
|
|
},
|
|
],
|
|
type: 'suggestion',
|
|
},
|
|
defaultOptions: [{}],
|
|
create(context, [options]) {
|
|
const sourceCode = context.getSourceCode();
|
|
const parserServices = util.getParserServices(context);
|
|
const checker = parserServices.program.getTypeChecker();
|
|
const compilerOptions = parserServices.program.getCompilerOptions();
|
|
/**
|
|
* Sometimes tuple types don't have ObjectFlags.Tuple set, like when they're being matched against an inferred type.
|
|
* So, in addition, check if there are integer properties 0..n and no other numeric keys
|
|
*/
|
|
function couldBeTupleType(type) {
|
|
const properties = type.getProperties();
|
|
if (properties.length === 0) {
|
|
return false;
|
|
}
|
|
let i = 0;
|
|
for (; i < properties.length; ++i) {
|
|
const name = properties[i].name;
|
|
if (String(i) !== name) {
|
|
if (i === 0) {
|
|
// if there are no integer properties, this is not a tuple
|
|
return false;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
for (; i < properties.length; ++i) {
|
|
if (String(+properties[i].name) === properties[i].name) {
|
|
return false; // if there are any other numeric properties, this is not a tuple
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
/**
|
|
* Returns true if there's a chance the variable has been used before a value has been assigned to it
|
|
*/
|
|
function isPossiblyUsedBeforeAssigned(node) {
|
|
const declaration = util.getDeclaration(checker, node);
|
|
if (!declaration) {
|
|
// don't know what the declaration is for some reason, so just assume the worst
|
|
return true;
|
|
}
|
|
if (
|
|
// non-strict mode doesn't care about used before assigned errors
|
|
(0, tsutils_1.isStrictCompilerOptionEnabled)(compilerOptions, 'strictNullChecks') &&
|
|
// ignore class properties as they are compile time guarded
|
|
// also ignore function arguments as they can't be used before defined
|
|
(0, tsutils_1.isVariableDeclaration)(declaration) &&
|
|
// is it `const x!: number`
|
|
declaration.initializer === undefined &&
|
|
declaration.exclamationToken === undefined &&
|
|
declaration.type !== undefined) {
|
|
// check if the defined variable type has changed since assignment
|
|
const declarationType = checker.getTypeFromTypeNode(declaration.type);
|
|
const type = util.getConstrainedTypeAtLocation(checker, node);
|
|
if (declarationType === type) {
|
|
// possibly used before assigned, so just skip it
|
|
// better to false negative and skip it, than false positive and fix to compile erroring code
|
|
//
|
|
// no better way to figure this out right now
|
|
// https://github.com/Microsoft/TypeScript/issues/31124
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
function isConstAssertion(node) {
|
|
return (node.type === utils_1.AST_NODE_TYPES.TSTypeReference &&
|
|
node.typeName.type === utils_1.AST_NODE_TYPES.Identifier &&
|
|
node.typeName.name === 'const');
|
|
}
|
|
return {
|
|
TSNonNullExpression(node) {
|
|
var _a;
|
|
if (((_a = node.parent) === null || _a === void 0 ? void 0 : _a.type) === utils_1.AST_NODE_TYPES.AssignmentExpression &&
|
|
node.parent.operator === '=') {
|
|
if (node.parent.left === node) {
|
|
context.report({
|
|
node,
|
|
messageId: 'contextuallyUnnecessary',
|
|
fix(fixer) {
|
|
return fixer.removeRange([
|
|
node.expression.range[1],
|
|
node.range[1],
|
|
]);
|
|
},
|
|
});
|
|
}
|
|
// for all other = assignments we ignore non-null checks
|
|
// this is because non-null assertions can change the type-flow of the code
|
|
// so whilst they might be unnecessary for the assignment - they are necessary
|
|
// for following code
|
|
return;
|
|
}
|
|
const originalNode = parserServices.esTreeNodeToTSNodeMap.get(node);
|
|
const type = util.getConstrainedTypeAtLocation(checker, originalNode.expression);
|
|
if (!util.isNullableType(type)) {
|
|
if (isPossiblyUsedBeforeAssigned(originalNode.expression)) {
|
|
return;
|
|
}
|
|
context.report({
|
|
node,
|
|
messageId: 'unnecessaryAssertion',
|
|
fix(fixer) {
|
|
return fixer.removeRange([
|
|
node.expression.range[1],
|
|
node.range[1],
|
|
]);
|
|
},
|
|
});
|
|
}
|
|
else {
|
|
// we know it's a nullable type
|
|
// so figure out if the variable is used in a place that accepts nullable types
|
|
const contextualType = util.getContextualType(checker, originalNode);
|
|
if (contextualType) {
|
|
// in strict mode you can't assign null to undefined, so we have to make sure that
|
|
// the two types share a nullable type
|
|
const typeIncludesUndefined = util.isTypeFlagSet(type, ts.TypeFlags.Undefined);
|
|
const typeIncludesNull = util.isTypeFlagSet(type, ts.TypeFlags.Null);
|
|
const contextualTypeIncludesUndefined = util.isTypeFlagSet(contextualType, ts.TypeFlags.Undefined);
|
|
const contextualTypeIncludesNull = util.isTypeFlagSet(contextualType, ts.TypeFlags.Null);
|
|
// make sure that the parent accepts the same types
|
|
// i.e. assigning `string | null | undefined` to `string | undefined` is invalid
|
|
const isValidUndefined = typeIncludesUndefined
|
|
? contextualTypeIncludesUndefined
|
|
: true;
|
|
const isValidNull = typeIncludesNull
|
|
? contextualTypeIncludesNull
|
|
: true;
|
|
if (isValidUndefined && isValidNull) {
|
|
context.report({
|
|
node,
|
|
messageId: 'contextuallyUnnecessary',
|
|
fix(fixer) {
|
|
return fixer.removeRange([
|
|
node.expression.range[1],
|
|
node.range[1],
|
|
]);
|
|
},
|
|
});
|
|
}
|
|
}
|
|
}
|
|
},
|
|
'TSAsExpression, TSTypeAssertion'(node) {
|
|
var _a;
|
|
if (((_a = options.typesToIgnore) === null || _a === void 0 ? void 0 : _a.includes(sourceCode.getText(node.typeAnnotation))) ||
|
|
isConstAssertion(node.typeAnnotation)) {
|
|
return;
|
|
}
|
|
const originalNode = parserServices.esTreeNodeToTSNodeMap.get(node);
|
|
const castType = checker.getTypeAtLocation(originalNode);
|
|
if ((0, tsutils_1.isTypeFlagSet)(castType, ts.TypeFlags.Literal) ||
|
|
((0, tsutils_1.isObjectType)(castType) &&
|
|
((0, tsutils_1.isObjectFlagSet)(castType, ts.ObjectFlags.Tuple) ||
|
|
couldBeTupleType(castType)))) {
|
|
// It's not always safe to remove a cast to a literal type or tuple
|
|
// type, as those types are sometimes widened without the cast.
|
|
return;
|
|
}
|
|
const uncastType = checker.getTypeAtLocation(originalNode.expression);
|
|
if (uncastType === castType) {
|
|
context.report({
|
|
node,
|
|
messageId: 'unnecessaryAssertion',
|
|
fix(fixer) {
|
|
if (originalNode.kind === ts.SyntaxKind.TypeAssertionExpression) {
|
|
const closingAngleBracket = sourceCode.getTokenAfter(node.typeAnnotation);
|
|
return (closingAngleBracket === null || closingAngleBracket === void 0 ? void 0 : closingAngleBracket.value) === '>'
|
|
? fixer.removeRange([
|
|
node.range[0],
|
|
closingAngleBracket.range[1],
|
|
])
|
|
: null;
|
|
}
|
|
return fixer.removeRange([
|
|
node.expression.range[1] + 1,
|
|
node.range[1],
|
|
]);
|
|
},
|
|
});
|
|
}
|
|
// TODO - add contextually unnecessary check for this
|
|
},
|
|
};
|
|
},
|
|
});
|
|
//# sourceMappingURL=no-unnecessary-type-assertion.js.map |