eslint-plugin-obsidianmd/dist/lib/rules/noTFileTFolderCast.js

Validates guidelines for Obsidian plugins

import { ESLintUtils } from "@typescript-eslint/utils";
const ruleCreator = ESLintUtils.RuleCreator((name) => `https://github.com/obsidianmd/eslint-plugin/blob/master/docs/rules/${name}.md`);
const BANNED_CAST_TYPES = new Set(["TFile", "TFolder"]);
export default ruleCreator({
    name: "no-tfile-tfolder-cast",
    meta: {
        type: "suggestion",
        docs: {
            description: "Disallow type casting to TFile or TFolder, suggesting instanceof checks instead.",
        },
        schema: [],
        messages: {
            avoidCast: "Avoid casting to '{{typeName}}'. Use an 'instanceof {{typeName}}' check to safely narrow the type.",
        },
        // This rule is not auto-fixable because the correction requires
        // changing the code's control flow (e.g., adding an if-block),
        // which is too complex and potentially breaking for an auto-fix.
    },
    defaultOptions: [],
    create(context) {
        // The handler for both TSAsExpression and TSTypeAssertion nodes.
        // It checks if the type being cast to is TFile or TFolder.
        const handler = (node) => {
            const typeAnnotation = node.typeAnnotation;
            // We only care about simple type references like `as TFile`
            if (typeAnnotation.type === "TSTypeReference" &&
                typeAnnotation.typeName.type === "Identifier") {
                const typeName = typeAnnotation.typeName.name;
                if (BANNED_CAST_TYPES.has(typeName)) {
                    context.report({
                        node: typeAnnotation,
                        messageId: "avoidCast",
                        data: {
                            typeName,
                        },
                    });
                }
            }
        };
        return {
            // Catches `value as TFile`
            TSAsExpression: handler,
            // Catches `<TFile>value`
            TSTypeAssertion: handler,
        };
    },
});