@vanta-inc/eslint-plugin-vanta/lib/rules/null-or-undefined-check.js

Custom ESLint rules for Vanta

"use strict";
/**
 * @fileoverview Prefer isSome(expr) to checking against undefined or null
 */
Object.defineProperty(exports, "__esModule", { value: true });
var utils_1 = require("@typescript-eslint/utils");
var rule = utils_1.ESLintUtils.RuleCreator(function (ruleName) {
    return "https://github.com/VantaInc/eslint-plugin-vanta/blob/main/docs/rules/" + ruleName + ".md";
})({
    name: "null-or-undefined-check",
    meta: {
        fixable: "code",
        docs: {
            description: "Use isSome(expr) to check against undefined or null.",
            recommended: "error",
        },
        messages: {
            default: "{{original}} should be {{replacement}}",
        },
        type: "suggestion",
        schema: [],
    },
    defaultOptions: [],
    create: function (context) {
        var sourceCode = context.getSourceCode();
        return {
            BinaryExpression: function (node) {
                var isEquals;
                if (node.operator === "==" || node.operator === "===") {
                    isEquals = true;
                }
                else if (node.operator === "!=" || node.operator === "!==") {
                    isEquals = false;
                }
                else {
                    return;
                }
                var variableExpr;
                if ((node.left.type === utils_1.AST_NODE_TYPES.Literal &&
                    node.left.value === null) ||
                    sourceCode.getText(node.left) === "undefined" // undefined is unfortunately an identifier type; assume that it isn't overridden
                ) {
                    variableExpr = node.right;
                }
                else if ((node.right.type === utils_1.AST_NODE_TYPES.Literal &&
                    node.right.value === null) ||
                    sourceCode.getText(node.right) === "undefined") {
                    variableExpr = node.left;
                }
                else {
                    return;
                }
                var text = sourceCode.getText(variableExpr);
                var replacement = (isEquals ? "!" : "") + "isSome(" + text + ")";
                var original = sourceCode.getText(node);
                context.report({
                    node: node,
                    data: {
                        original: original,
                        replacement: replacement,
                    },
                    messageId: "default",
                    fix: function (fixer) {
                        return [fixer.replaceText(node, replacement)];
                    },
                });
            },
        };
    },
});
module.exports = rule;
exports.default = rule;