Function expandStringImpl

Extension/src/expand.ts:66–135

Returns [expandedString, didReplacement]

(input: string, options: ExpansionOptions)

/** Returns [expandedString, didReplacement] */
async function expandStringImpl(input: string, options: ExpansionOptions): Promise<[string, boolean]> {
    if (!input) {
        return [input, false];
    }

    // We accumulate a list of substitutions that we need to make, preventing
    // recursively expanding or looping forever on bad replacements
    const subs: Map<string, string> = new Map<string, string>();

    const var_re: RegExp = /\$\{(\w+)\}/g;
    let match: RegExpMatchArray | null = null;
    while (match = var_re.exec(input)) {
        const full: string = match[0];
        const key: string = match[1];
        if (key !== 'dollar') {
            // Replace dollar sign at the very end of the expanding process
            const repl: string = options.vars[key];
            if (!repl) {
                void getOutputChannelLogger().showWarningMessage(localize('invalid.var.reference', 'Invalid variable reference {0} in string: {1}.', full, input));
            } else {
                subs.set(full, repl);
            }
        }
    }

    // Regular expression for variable value (between the variable suffix and the next ending curly bracket):
    // .+? matches any character (except line terminators) between one and unlimited times,
    // as few times as possible, expanding as needed (lazy)
    const varValueRegexp: string = ".+?";
    const env_re: RegExp = RegExp(`\\$\\{env:(${varValueRegexp})\\}`, "g");
    while (match = env_re.exec(input)) {
        const full: string = match[0];
        const varname: string = match[1];
        if (process.env[varname] === undefined) {
            void getOutputChannelLogger().showWarningMessage(localize('env.var.not.found', 'Environment variable {0} not found', varname));
        }
        const repl: string = process.env[varname] || '';
        subs.set(full, repl);
    }

    const command_re: RegExp = RegExp(`\\$\\{command:(${varValueRegexp})\\}`, "g");
    while (match = command_re.exec(input)) {
        if (options.doNotSupportCommands) {
            void getOutputChannelLogger().showWarningMessage(localize('commands.not.supported', 'Commands are not supported for string: {0}.', input));
            break;
        }
        const full: string = match[0];
        const command: string = match[1];
        if (subs.has(full)) {
            continue; // Don't execute commands more than once per string
        }
        try {
            const command_ret: unknown = await vscode.commands.executeCommand(command, options.vars.workspaceFolder);
            subs.set(full, `${command_ret}`);
        } catch (e: any) {
            void getOutputChannelLogger().showWarningMessage(localize('exception.executing.command', 'Exception while executing command {0} for string: {1} {2}.', command, input, e));
        }
    }