@typescript-eslint/eslint-plugin
Version:
TypeScript plugin for ESLint
93 lines (92 loc) • 4.05 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
const utils_1 = require("@typescript-eslint/utils");
const util_1 = require("../util");
exports.default = (0, util_1.createRule)({
name: 'no-non-null-assertion',
meta: {
type: 'problem',
docs: {
description: 'Disallow non-null assertions using the `!` postfix operator',
recommended: 'strict',
},
hasSuggestions: true,
messages: {
noNonNull: 'Forbidden non-null assertion.',
suggestOptionalChain: 'Consider using the optional chain operator `?.` instead. This operator includes runtime checks, so it is safer than the compile-only non-null assertion operator.',
},
schema: [],
},
defaultOptions: [],
create(context) {
return {
TSNonNullExpression(node) {
const suggest = [];
// it always exists in non-null assertion
const nonNullOperator = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(node.expression, util_1.isNonNullAssertionPunctuator), util_1.NullThrowsReasons.MissingToken('!', 'expression'));
function replaceTokenWithOptional() {
return fixer => fixer.replaceText(nonNullOperator, '?.');
}
function removeToken() {
return fixer => fixer.remove(nonNullOperator);
}
if (node.parent.type === utils_1.AST_NODE_TYPES.MemberExpression &&
node.parent.object === node) {
if (!node.parent.optional) {
if (node.parent.computed) {
// it is x![y]?.z
suggest.push({
messageId: 'suggestOptionalChain',
fix: replaceTokenWithOptional(),
});
}
else {
// it is x!.y?.z
suggest.push({
messageId: 'suggestOptionalChain',
fix(fixer) {
// x!.y?.z
// ^ punctuator
const punctuator = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(nonNullOperator), util_1.NullThrowsReasons.MissingToken('.', '!'));
return [
fixer.remove(nonNullOperator),
fixer.insertTextBefore(punctuator, '?'),
];
},
});
}
}
else {
// it is x!?.[y].z or x!?.y.z
suggest.push({
messageId: 'suggestOptionalChain',
fix: removeToken(),
});
}
}
else if (node.parent.type === utils_1.AST_NODE_TYPES.CallExpression &&
node.parent.callee === node) {
if (!node.parent.optional) {
// it is x.y?.z!()
suggest.push({
messageId: 'suggestOptionalChain',
fix: replaceTokenWithOptional(),
});
}
else {
// it is x.y.z!?.()
suggest.push({
messageId: 'suggestOptionalChain',
fix: removeToken(),
});
}
}
context.report({
node,
messageId: 'noNonNull',
suggest,
});
},
};
},
});