compiler-explorer/lib/assert.ts

// Copyright (c) 2022, Compiler Explorer Authors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

import * as fs from 'node:fs';
import path from 'node:path';

import {isString} from '../shared/common-utils.js';
import {parse} from '../shared/stacktrace.js';

// Helper for cross-platform path handling in tests
export function normalizePath(filePath: string): string {
    return filePath.split(path.sep).join('/');
}

let ce_base_directory = '';

const filePrefix = 'file://';

export function setBaseDirectory(base_url_path: URL) {
    ce_base_directory = base_url_path.pathname;
}

// Explicitly export for testing purposes - not part of the public API
export function removeFileProtocol(path: string) {
    if (path.startsWith(filePrefix)) {
        return path.slice(filePrefix.length);
    }
    return path;
}

// Explicitly export for testing purposes - not part of the public API
export function check_path(parent: string, directory: string) {
    // https://stackoverflow.com/a/45242825/15675011
    const relative = path.relative(parent, directory);
    if (relative && !relative.startsWith('..') && !path.isAbsolute(relative)) {
        // Normalize separators to forward slashes for consistent behavior across platforms
        return normalizePath(relative);
    }
    return false;
}

// Explicitly export for testing purposes - not part of the public API
export function get_diagnostic() {
    const e = new Error();
    const trace = parse(e);
    if (trace.length >= 4) {
        const invoker_frame = trace[3];
        if (invoker_frame.fileName && invoker_frame.lineNumber) {
            // Just out of an abundance of caution...
            const relative = check_path(ce_base_directory, removeFileProtocol(invoker_frame.fileName));
            if (relative) {
                try {
                    const file = fs.readFileSync(invoker_frame.fileName, 'utf8');
                    const lines = file.split('\n');
                    return {
                        file: relative,
                        line: invoker_frame.lineNumber,
                        src: lines[invoker_frame.lineNumber - 1].trim(),
                    };
                } catch (e: any) {}
            }
        }
    }
}

function fail(fail_message: string, user_message: string | undefined, args: any[]): never {
    // Assertions will look like:
    // Assertion failed
    // Assertion failed: Foobar
    // Assertion failed: Foobar, [{"foo": "bar"}]
    // Assertion failed: Foobar, [{"foo": "bar"}], at `assert(x.foo.length < 2, "Foobar", x)`
    let assert_line = fail_message;
    if (user_message) {
        assert_line += `: ${user_message}`;
    }
    if (args.length > 0) {
        try {
            assert_line += ', ' + JSON.stringify(args);
        } catch (e) {}
    }

    const diagnostic = get_diagnostic();
    if (diagnostic) {
        throw new Error(assert_line + `, at ${diagnostic.file}:${diagnostic.line} \`${diagnostic.src}\``);
    }
    throw new Error(assert_line);
}

// Using `unknown` instead of generic implementation due to:
// https://github.com/microsoft/TypeScript/issues/60130
export function assert(c: unknown, message?: string, ...extra_info: any[]): asserts c {
    if (!c) {
        fail('Assertion failed', message, extra_info);
    }
}

export function unwrap<T>(x: T | undefined | null, message?: string, ...extra_info: any[]): T {
    if (x === undefined || x === null) {
        fail('Unwrap failed', message, extra_info);
    }
    return x;
}

// Take a type value that is maybe a string and ensure it is
// T is syntax sugar for unwrapping to a string union
export function unwrapString<T extends string>(x: any, message?: string, ...extra_info: any[]): T {
    if (!isString(x)) {
        fail('String unwrap failed', message, extra_info);
    }
    return x as T;
}