@typescript-eslint/eslint-plugin
Version:
TypeScript plugin for ESLint
393 lines (392 loc) • 17.8 kB
JavaScript
"use strict";
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}
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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 () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
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};
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};
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if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
const utils_1 = require("@typescript-eslint/utils");
const tsutils = __importStar(require("ts-api-utils"));
const ts = __importStar(require("typescript"));
const util_1 = require("../util");
const getMemberHeadLoc_1 = require("../util/getMemberHeadLoc");
const functionScopeBoundaries = [
utils_1.AST_NODE_TYPES.ArrowFunctionExpression,
utils_1.AST_NODE_TYPES.FunctionDeclaration,
utils_1.AST_NODE_TYPES.FunctionExpression,
utils_1.AST_NODE_TYPES.MethodDefinition,
].join(', ');
exports.default = (0, util_1.createRule)({
name: 'prefer-readonly',
meta: {
type: 'suggestion',
docs: {
description: "Require private members to be marked as `readonly` if they're never modified outside of the constructor",
requiresTypeChecking: true,
},
fixable: 'code',
messages: {
preferReadonly: "Member '{{name}}' is never reassigned; mark it as `readonly`.",
},
schema: [
{
type: 'object',
additionalProperties: false,
properties: {
onlyInlineLambdas: {
type: 'boolean',
description: 'Whether to restrict checking only to members immediately assigned a lambda value.',
},
},
},
],
},
defaultOptions: [{ onlyInlineLambdas: false }],
create(context, [{ onlyInlineLambdas }]) {
const services = (0, util_1.getParserServices)(context);
const checker = services.program.getTypeChecker();
const classScopeStack = [];
function handlePropertyAccessExpression(node, parent, classScope) {
if (ts.isBinaryExpression(parent)) {
handleParentBinaryExpression(node, parent, classScope);
return;
}
if (ts.isDeleteExpression(parent) || isDestructuringAssignment(node)) {
classScope.addVariableModification(node);
return;
}
if (ts.isPostfixUnaryExpression(parent) ||
ts.isPrefixUnaryExpression(parent)) {
handleParentPostfixOrPrefixUnaryExpression(parent, classScope);
}
}
function handleParentBinaryExpression(node, parent, classScope) {
if (parent.left === node &&
tsutils.isAssignmentKind(parent.operatorToken.kind)) {
classScope.addVariableModification(node);
}
}
function handleParentPostfixOrPrefixUnaryExpression(node, classScope) {
if (node.operator === ts.SyntaxKind.PlusPlusToken ||
node.operator === ts.SyntaxKind.MinusMinusToken) {
classScope.addVariableModification(node.operand);
}
}
function isDestructuringAssignment(node) {
let current = node.parent;
while (current) {
const parent = current.parent;
if (ts.isObjectLiteralExpression(parent) ||
ts.isArrayLiteralExpression(parent) ||
ts.isSpreadAssignment(parent) ||
(ts.isSpreadElement(parent) &&
ts.isArrayLiteralExpression(parent.parent))) {
current = parent;
}
else if (ts.isBinaryExpression(parent) &&
!ts.isPropertyAccessExpression(current)) {
return (parent.left === current &&
parent.operatorToken.kind === ts.SyntaxKind.EqualsToken);
}
else {
break;
}
}
return false;
}
function isFunctionScopeBoundaryInStack(node) {
if (classScopeStack.length === 0) {
return false;
}
const tsNode = services.esTreeNodeToTSNodeMap.get(node);
if (ts.isConstructorDeclaration(tsNode)) {
return false;
}
return tsutils.isFunctionScopeBoundary(tsNode);
}
function getEsNodesFromViolatingNode(violatingNode) {
return {
esNode: services.tsNodeToESTreeNodeMap.get(violatingNode),
nameNode: services.tsNodeToESTreeNodeMap.get(violatingNode.name),
};
}
function getTypeAnnotationForViolatingNode(node, type, initializerType) {
const annotation = checker.typeToString(type);
// verify the about-to-be-added type annotation is in-scope
if (tsutils.isTypeFlagSet(initializerType, ts.TypeFlags.EnumLiteral)) {
const scope = context.sourceCode.getScope(node);
const variable = utils_1.ASTUtils.findVariable(scope, annotation);
if (variable == null) {
return null;
}
const definition = variable.defs.find(def => def.isTypeDefinition);
if (definition == null) {
return null;
}
const definitionType = services.getTypeAtLocation(definition.node);
if (definitionType !== type) {
return null;
}
}
return annotation;
}
return {
[`${functionScopeBoundaries}:exit`](node) {
if (utils_1.ASTUtils.isConstructor(node)) {
classScopeStack[classScopeStack.length - 1].exitConstructor();
}
else if (isFunctionScopeBoundaryInStack(node)) {
classScopeStack[classScopeStack.length - 1].exitNonConstructor();
}
},
'ClassDeclaration, ClassExpression'(node) {
classScopeStack.push(new ClassScope(checker, services.esTreeNodeToTSNodeMap.get(node), onlyInlineLambdas));
},
'ClassDeclaration, ClassExpression:exit'() {
const finalizedClassScope = (0, util_1.nullThrows)(classScopeStack.pop(), 'Stack should exist on class exit');
for (const violatingNode of finalizedClassScope.finalizeUnmodifiedPrivateNonReadonlys()) {
const { esNode, nameNode } = getEsNodesFromViolatingNode(violatingNode);
const reportNodeOrLoc = (() => {
switch (esNode.type) {
case utils_1.AST_NODE_TYPES.MethodDefinition:
case utils_1.AST_NODE_TYPES.PropertyDefinition:
case utils_1.AST_NODE_TYPES.TSAbstractMethodDefinition:
return { loc: (0, getMemberHeadLoc_1.getMemberHeadLoc)(context.sourceCode, esNode) };
case utils_1.AST_NODE_TYPES.TSParameterProperty:
return {
loc: (0, getMemberHeadLoc_1.getParameterPropertyHeadLoc)(context.sourceCode, esNode, nameNode.name),
};
default:
return { node: esNode };
}
})();
const typeAnnotation = (() => {
if (esNode.type !== utils_1.AST_NODE_TYPES.PropertyDefinition) {
return null;
}
if (esNode.typeAnnotation || !esNode.value) {
return null;
}
if (nameNode.type !== utils_1.AST_NODE_TYPES.Identifier) {
return null;
}
const hasConstructorModifications = finalizedClassScope.memberHasConstructorModifications(nameNode.name);
if (!hasConstructorModifications) {
return null;
}
const violatingType = services.getTypeAtLocation(esNode);
const initializerType = services.getTypeAtLocation(esNode.value);
// if the RHS is a literal, its type would be narrowed, while the
// type of the initializer (which isn't `readonly`) would be the
// widened type
if (initializerType === violatingType) {
return null;
}
if (!tsutils.isLiteralType(initializerType)) {
return null;
}
return getTypeAnnotationForViolatingNode(esNode, violatingType, initializerType);
})();
context.report({
...reportNodeOrLoc,
messageId: 'preferReadonly',
data: {
name: context.sourceCode.getText(nameNode),
},
*fix(fixer) {
yield fixer.insertTextBefore(nameNode, 'readonly ');
if (typeAnnotation) {
yield fixer.insertTextAfter(nameNode, `: ${typeAnnotation}`);
}
},
});
}
},
[functionScopeBoundaries](node) {
if (utils_1.ASTUtils.isConstructor(node)) {
classScopeStack[classScopeStack.length - 1].enterConstructor(services.esTreeNodeToTSNodeMap.get(node));
}
else if (isFunctionScopeBoundaryInStack(node)) {
classScopeStack[classScopeStack.length - 1].enterNonConstructor();
}
},
MemberExpression(node) {
if (classScopeStack.length !== 0 && !node.computed) {
const tsNode = services.esTreeNodeToTSNodeMap.get(node);
handlePropertyAccessExpression(tsNode, tsNode.parent, classScopeStack[classScopeStack.length - 1]);
}
},
};
},
});
const OUTSIDE_CONSTRUCTOR = -1;
const DIRECTLY_INSIDE_CONSTRUCTOR = 0;
var TypeToClassRelation;
(function (TypeToClassRelation) {
TypeToClassRelation[TypeToClassRelation["ClassAndInstance"] = 0] = "ClassAndInstance";
TypeToClassRelation[TypeToClassRelation["Class"] = 1] = "Class";
TypeToClassRelation[TypeToClassRelation["Instance"] = 2] = "Instance";
TypeToClassRelation[TypeToClassRelation["None"] = 3] = "None";
})(TypeToClassRelation || (TypeToClassRelation = {}));
class ClassScope {
checker;
onlyInlineLambdas;
classType;
constructorScopeDepth = OUTSIDE_CONSTRUCTOR;
memberVariableModifications = new Set();
memberVariableWithConstructorModifications = new Set();
privateModifiableMembers = new Map();
privateModifiableStatics = new Map();
staticVariableModifications = new Set();
constructor(checker, classNode, onlyInlineLambdas) {
this.checker = checker;
this.onlyInlineLambdas = onlyInlineLambdas;
const classType = checker.getTypeAtLocation(classNode);
if (tsutils.isIntersectionType(classType)) {
this.classType = classType.types[0];
}
else {
this.classType = classType;
}
for (const member of classNode.members) {
if (ts.isPropertyDeclaration(member)) {
this.addDeclaredVariable(member);
}
}
}
addDeclaredVariable(node) {
if (!(tsutils.isModifierFlagSet(node, ts.ModifierFlags.Private) ||
node.name.kind === ts.SyntaxKind.PrivateIdentifier) ||
tsutils.isModifierFlagSet(node, ts.ModifierFlags.Accessor | ts.ModifierFlags.Readonly) ||
ts.isComputedPropertyName(node.name)) {
return;
}
if (this.onlyInlineLambdas &&
node.initializer != null &&
!ts.isArrowFunction(node.initializer)) {
return;
}
(tsutils.isModifierFlagSet(node, ts.ModifierFlags.Static)
? this.privateModifiableStatics
: this.privateModifiableMembers).set(node.name.getText(), node);
}
addVariableModification(node) {
const modifierType = this.checker.getTypeAtLocation(node.expression);
const relationOfModifierTypeToClass = this.getTypeToClassRelation(modifierType);
if (relationOfModifierTypeToClass === TypeToClassRelation.Instance &&
this.constructorScopeDepth === DIRECTLY_INSIDE_CONSTRUCTOR) {
this.memberVariableWithConstructorModifications.add(node.name.text);
return;
}
if (relationOfModifierTypeToClass === TypeToClassRelation.Instance ||
relationOfModifierTypeToClass === TypeToClassRelation.ClassAndInstance) {
this.memberVariableModifications.add(node.name.text);
}
if (relationOfModifierTypeToClass === TypeToClassRelation.Class ||
relationOfModifierTypeToClass === TypeToClassRelation.ClassAndInstance) {
this.staticVariableModifications.add(node.name.text);
}
}
enterConstructor(node) {
this.constructorScopeDepth = DIRECTLY_INSIDE_CONSTRUCTOR;
for (const parameter of node.parameters) {
if (tsutils.isModifierFlagSet(parameter, ts.ModifierFlags.Private)) {
this.addDeclaredVariable(parameter);
}
}
}
enterNonConstructor() {
if (this.constructorScopeDepth !== OUTSIDE_CONSTRUCTOR) {
this.constructorScopeDepth += 1;
}
}
exitConstructor() {
this.constructorScopeDepth = OUTSIDE_CONSTRUCTOR;
}
exitNonConstructor() {
if (this.constructorScopeDepth !== OUTSIDE_CONSTRUCTOR) {
this.constructorScopeDepth -= 1;
}
}
finalizeUnmodifiedPrivateNonReadonlys() {
this.memberVariableModifications.forEach(variableName => {
this.privateModifiableMembers.delete(variableName);
});
this.staticVariableModifications.forEach(variableName => {
this.privateModifiableStatics.delete(variableName);
});
return [
...this.privateModifiableMembers.values(),
...this.privateModifiableStatics.values(),
];
}
getTypeToClassRelation(type) {
if (type.isIntersection()) {
let result = TypeToClassRelation.None;
for (const subType of type.types) {
const subTypeResult = this.getTypeToClassRelation(subType);
switch (subTypeResult) {
case TypeToClassRelation.Class:
if (result === TypeToClassRelation.Instance) {
return TypeToClassRelation.ClassAndInstance;
}
result = TypeToClassRelation.Class;
break;
case TypeToClassRelation.Instance:
if (result === TypeToClassRelation.Class) {
return TypeToClassRelation.ClassAndInstance;
}
result = TypeToClassRelation.Instance;
break;
}
}
return result;
}
if (type.isUnion()) {
// any union of class/instance and something else will prevent access to
// private members, so we assume that union consists only of classes
// or class instances, because otherwise tsc will report an error
return this.getTypeToClassRelation(type.types[0]);
}
if (!type.getSymbol() || !(0, util_1.typeIsOrHasBaseType)(type, this.classType)) {
return TypeToClassRelation.None;
}
const typeIsClass = tsutils.isObjectType(type) &&
tsutils.isObjectFlagSet(type, ts.ObjectFlags.Anonymous);
if (typeIsClass) {
return TypeToClassRelation.Class;
}
return TypeToClassRelation.Instance;
}
memberHasConstructorModifications(name) {
return this.memberVariableWithConstructorModifications.has(name);
}
}