@typescript-eslint/eslint-plugin
Version:
TypeScript plugin for ESLint
144 lines (143 loc) • 6.92 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
const utils_1 = require("@typescript-eslint/utils");
const util_1 = require("../util");
const noEmptyMessage = (emptyType) => [
`${emptyType} allows any non-nullish value, including literals like \`0\` and \`""\`.`,
"- If that's what you want, disable this lint rule with an inline comment or configure the '{{ option }}' rule option.",
'- If you want a type meaning "any object", you probably want `object` instead.',
'- If you want a type meaning "any value", you probably want `unknown` instead.',
].join('\n');
exports.default = (0, util_1.createRule)({
name: 'no-empty-object-type',
meta: {
type: 'suggestion',
docs: {
description: 'Disallow accidentally using the "empty object" type',
recommended: 'recommended',
},
hasSuggestions: true,
messages: {
noEmptyInterface: noEmptyMessage('An empty interface declaration'),
noEmptyInterfaceWithSuper: 'An interface declaring no members is equivalent to its supertype.',
noEmptyObject: noEmptyMessage('The `{}` ("empty object") type'),
replaceEmptyInterface: 'Replace empty interface with `{{replacement}}`.',
replaceEmptyInterfaceWithSuper: 'Replace empty interface with a type alias.',
replaceEmptyObjectType: 'Replace `{}` with `{{replacement}}`.',
},
schema: [
{
type: 'object',
additionalProperties: false,
properties: {
allowInterfaces: {
type: 'string',
description: 'Whether to allow empty interfaces.',
enum: ['always', 'never', 'with-single-extends'],
},
allowObjectTypes: {
type: 'string',
description: 'Whether to allow empty object type literals.',
enum: ['always', 'never'],
},
allowWithName: {
type: 'string',
description: 'A stringified regular expression to allow interfaces and object type aliases with the configured name.',
},
},
},
],
},
defaultOptions: [
{
allowInterfaces: 'never',
allowObjectTypes: 'never',
},
],
create(context, [{ allowInterfaces, allowObjectTypes, allowWithName }]) {
const allowWithNameTester = allowWithName
? new RegExp(allowWithName, 'u')
: undefined;
return {
...(allowInterfaces !== 'always' && {
TSInterfaceDeclaration(node) {
if (allowWithNameTester?.test(node.id.name)) {
return;
}
const extend = node.extends;
if (node.body.body.length !== 0 ||
(extend.length === 1 &&
allowInterfaces === 'with-single-extends') ||
extend.length > 1) {
return;
}
const scope = context.sourceCode.getScope(node);
const mergedWithClassDeclaration = scope.set
.get(node.id.name)
?.defs.some(def => def.node.type === utils_1.AST_NODE_TYPES.ClassDeclaration);
if (extend.length === 0) {
context.report({
node: node.id,
messageId: 'noEmptyInterface',
data: { option: 'allowInterfaces' },
...(!mergedWithClassDeclaration && {
suggest: ['object', 'unknown'].map(replacement => ({
messageId: 'replaceEmptyInterface',
data: { replacement },
fix(fixer) {
const id = context.sourceCode.getText(node.id);
const typeParam = node.typeParameters
? context.sourceCode.getText(node.typeParameters)
: '';
return fixer.replaceText(node, `type ${id}${typeParam} = ${replacement}`);
},
})),
}),
});
return;
}
context.report({
node: node.id,
messageId: 'noEmptyInterfaceWithSuper',
...(!mergedWithClassDeclaration && {
suggest: [
{
messageId: 'replaceEmptyInterfaceWithSuper',
fix(fixer) {
const extended = context.sourceCode.getText(extend[0]);
const id = context.sourceCode.getText(node.id);
const typeParam = node.typeParameters
? context.sourceCode.getText(node.typeParameters)
: '';
return fixer.replaceText(node, `type ${id}${typeParam} = ${extended}`);
},
},
],
}),
});
},
}),
...(allowObjectTypes !== 'always' && {
TSTypeLiteral(node) {
if (node.members.length ||
node.parent.type === utils_1.AST_NODE_TYPES.TSIntersectionType ||
(allowWithNameTester &&
node.parent.type === utils_1.AST_NODE_TYPES.TSTypeAliasDeclaration &&
allowWithNameTester.test(node.parent.id.name))) {
return;
}
context.report({
node,
messageId: 'noEmptyObject',
data: { option: 'allowObjectTypes' },
suggest: ['object', 'unknown'].map(replacement => ({
messageId: 'replaceEmptyObjectType',
data: { replacement },
fix: (fixer) => fixer.replaceText(node, replacement),
})),
});
},
}),
};
},
});