matrix-react-sdk/test/utils/SnakedObject-test.ts

/*
Copyright 2022 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import { SnakedObject, snakeToCamel } from "../../src/utils/SnakedObject";

describe("snakeToCamel", () => {
    it("should convert snake_case to camelCase in simple scenarios", () => {
        expect(snakeToCamel("snake_case")).toBe("snakeCase");
        expect(snakeToCamel("snake_case_but_longer")).toBe("snakeCaseButLonger");
        expect(snakeToCamel("numbered_123")).toBe("numbered123"); // not a thing we would see normally
    });

    // Not really something we expect to see, but it's defined behaviour of the function
    it("should not camelCase a trailing or leading underscore", () => {
        expect(snakeToCamel("_snake")).toBe("_snake");
        expect(snakeToCamel("snake_")).toBe("snake_");
        expect(snakeToCamel("_snake_case")).toBe("_snakeCase");
        expect(snakeToCamel("snake_case_")).toBe("snakeCase_");
    });

    // Another thing we don't really expect to see, but is "defined behaviour"
    it("should be predictable with double underscores", () => {
        expect(snakeToCamel("__snake__")).toBe("_Snake_");
        expect(snakeToCamel("snake__case")).toBe("snake_case");
    });
});

describe("SnakedObject", () => {
    /* eslint-disable camelcase*/
    const input = {
        snake_case: "woot",
        snakeCase: "oh no", // ensure different value from snake_case for tests
        camelCase: "fallback",
    };
    const snake = new SnakedObject(input);
    /* eslint-enable camelcase*/

    it("should prefer snake_case keys", () => {
        expect(snake.get("snake_case")).toBe(input.snake_case);
        expect(snake.get("snake_case", "camelCase")).toBe(input.snake_case);
    });

    it("should fall back to camelCase keys when needed", () => {
        // @ts-ignore - we're deliberately supplying a key that doesn't exist
        expect(snake.get("camel_case")).toBe(input.camelCase);

        // @ts-ignore - we're deliberately supplying a key that doesn't exist
        expect(snake.get("e_no_exist", "camelCase")).toBe(input.camelCase);
    });
});