pve-eslint/eslint/tests/lib/shared/traverser.js

"use strict";

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

const assert = require("chai").assert;
const Traverser = require("../../../lib/shared/traverser");

//------------------------------------------------------------------------------
// Tests
//------------------------------------------------------------------------------

describe("Traverser", () => {
    it("traverses all keys except 'parent', 'leadingComments', and 'trailingComments'", () => {
        const traverser = new Traverser();
        const fakeAst = {
            type: "Program",
            body: [
                {
                    type: "ExpressionStatement",
                    leadingComments: {
                        type: "Line"
                    },
                    trailingComments: {
                        type: "Block"
                    }
                },
                {
                    type: "FooStatement",
                    foo: {
                        type: "BarStatement"
                    }
                }
            ]
        };

        fakeAst.body[0].parent = fakeAst;

        const enteredNodes = [];
        const exitedNodes = [];

        traverser.traverse(fakeAst, {
            enter: node => enteredNodes.push(node),
            leave: node => exitedNodes.push(node)
        });

        assert.deepStrictEqual(enteredNodes, [fakeAst, fakeAst.body[0], fakeAst.body[1], fakeAst.body[1].foo]);
        assert.deepStrictEqual(exitedNodes, [fakeAst.body[0], fakeAst.body[1].foo, fakeAst.body[1], fakeAst]);
    });

    it("traverses AST as using 'visitorKeys' option if given", () => {
        const traverser = new Traverser();
        const fakeAst = {
            type: "Program",
            body: [
                {
                    type: "ClassDeclaration",
                    id: {
                        type: "Identifier"
                    },
                    superClass: null,
                    body: {
                        type: "ClassBody",
                        body: []
                    },
                    experimentalDecorators: [
                        {
                            type: "Decorator",
                            expression: {}
                        }
                    ]
                }
            ]
        };

        fakeAst.body[0].parent = fakeAst;

        const visited = [];

        // with 'visitorKeys' option to traverse decorators.
        traverser.traverse(fakeAst, {
            enter: node => visited.push(node.type),
            visitorKeys: Object.assign({}, Traverser.DEFAULT_VISITOR_KEYS, {
                ClassDeclaration: Traverser.DEFAULT_VISITOR_KEYS.ClassDeclaration.concat(["experimentalDecorators"])
            })
        });
        assert.deepStrictEqual(visited, ["Program", "ClassDeclaration", "Identifier", "ClassBody", "Decorator"]);
    });
});