@addon24/eslint-config/rules/no-magic-values.js

ESLint configuration rules for WorldOfTextcraft projects - Centralized configuration for all project types

export default {
  rules: {
    "no-magic-values": {
          meta: {
            type: "problem",
            docs: {
              description: "Disallow magic numbers and magic strings",
              category: "Best Practices",
              recommended: true,
            },
            messages: {
              magicNumber: "Magic Number '{{value}}' found. Use a named constant instead.",
              magicString: "Magic String '{{value}}' found. Use a named constant instead.",
            },
            schema: [
              {
                type: "object",
                properties: {
                  ignoreNumbers: {
                    type: "array",
                    items: { type: "number" },
                    description: "Numbers to ignore (e.g., 0, 1, -1)",
                    default: [0, 1, -1]
                  },
                  ignoreStrings: {
                    type: "array",
                    items: { type: "string" },
                    description: "Strings to ignore (e.g., empty string)",
                    default: [""]
                  }
                },
                additionalProperties: false
              }
            ]
          },

      create(context) {
        const options = context.options[0] || {};
        const ignoreNumbers = options.ignoreNumbers || [0, 1, -1];
        const ignoreStrings = options.ignoreStrings || [""];

        function checkLiteral(node) {
          if (node.type === "Literal") {
            // Skip if it's inside a variable declaration (constant definition)
            if (node.parent && node.parent.type === "VariableDeclarator") {
              return;
            }

            if (typeof node.value === "number") {
              // Ignore configured numbers
              if (ignoreNumbers.includes(node.value)) {
                return;
              }

              context.report({
                node,
                messageId: "magicNumber",
                data: {
                  value: node.value,
                },
              });
            } else if (typeof node.value === "string") {
              // Ignore configured strings
              if (ignoreStrings.includes(node.value)) {
                return;
              }

              context.report({
                node,
                messageId: "magicString",
                data: {
                  value: node.value,
                },
              });
            }
          }
        }

        return {
          Literal: checkLiteral,
        };
      },
    },
  },
};