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GitHub Issues 默认过滤器

替换 GitHub issues 的默认过滤器

// ==UserScript==
// @name               GitHub Default Issues Filter
// @name:zh-CN         GitHub Issues 默认过滤器
// @description        Replaces GitHub issue's default filter
// @description:zh-CN  替换 GitHub issues 的默认过滤器
// @version            0.1
// @author             guansss
// @namespace          https://github.com/guansss
// @source             https://github.com/guansss/userscripts
// @supportURL         https://github.com/guansss/userscripts/issues
// @match              *://github.com/*
// @run-at             document-start
// @grant              GM_info
// @license            MIT
// @noframes
// ==/UserScript==

function _script_main() {
    'use strict';

    const ready = new Promise((resolve) => {
        if (document.readyState === 'loading') {
            document.addEventListener('DOMContentLoaded', () => resolve);
        } else {
            resolve();
        }
    });

    function hookMethod(object, method, callback) {
        const original = object[method];

        object[method] = function () {
            callback.apply(this, arguments);
            return original.apply(this, arguments);
        };
    }

    let log;

    setLogger(console.log);

    function setLogger(logger) {
        log = logger.bind(console, `[${GM_info.script.name}]`);
    }

    /**
     * Periodically calls given function until it returns true.
     */
    function repeat(fn, interval = 200) {
        if (fn()) {
            return 0;
        }

        const id = setInterval(() => {
            try {
                fn() && clearInterval(id);
            } catch (e) {
                log(e);
                clearInterval(id);
            }
        }, interval);

        return id;
    }

    /**
     * Periodically calls given function until the return value is truthy.
     * @returns A CancelablePromise that resolves with the function's return value when truthy.
     */
    function until(fn, interval = 0) {
        let cancelled = false;

        const promise = new Promise((resolve, reject) =>
            repeat(() => {
                if (cancelled) {
                    return true;
                }

                try {
                    const result = fn();

                    if (result) {
                        resolve(result);

                        // break the repeat() loop
                        return true;
                    }
                } catch (e) {
                    reject(e);
                    return true;
                }
            }, interval)
        );

        promise.cancel = () => (cancelled = true);

        return promise;
    }

    const urlRegex = /.*issues\/?$/;
    const defaultFilters = 'is:issue is:open ';
    const targetFilters = 'is:issue';

    let currentTask;

    function cancelCurrentTask() {
        currentTask && currentTask.cancel();
    }

    function check(url) {
        if (urlRegex.test(url)) {
            cancelCurrentTask();

            currentTask = until(() => {
                const input = document.getElementById('js-issues-search');

                if (input && input.parentElement && input.parentElement.tagName === 'FORM') {
                    // when navigating from pull requests to issues, the input is persisted until navigation completes,
                    // so we should ensure the input value is as expected
                    if (input.value === defaultFilters) {
                        input.value = targetFilters;
                        input.parentElement.dispatchEvent(new SubmitEvent('submit', { bubbles: true }));

                        return true;
                    }

                    // cancel current task whenever the input is changed by user, usually this won't happen
                    // since the interval is very short, but just in case the user is Shining Finger
                    input.addEventListener('input', cancelCurrentTask, { once: true });
                }
            }, 100);
        }
    }

    const handleStateChange = (data, unused, url) => {
        if (url instanceof URL) {
            url = url.href;
        }

        if (url) {
            check(url);
        }
    };

    hookMethod(history, 'pushState', handleStateChange);
    hookMethod(history, 'replaceState', handleStateChange);

    ready.then(() => check(location.href));
}

_script_main();