shelving/util/debug.js

Toolkit for using data in JavaScript.

/** Debug a random value as a string. */
export function debug(value, depth = 1) {
    if (value === null)
        return "null";
    if (value === undefined)
        return "undefined";
    if (typeof value === "boolean")
        return value ? "true" : "false";
    if (typeof value === "string")
        return debugString(value);
    if (typeof value === "number")
        return value.toString();
    if (typeof value === "symbol")
        return value.toString();
    if (typeof value === "function")
        return `function ${value.name || ""}()`;
    if (typeof value === "object") {
        if (value instanceof Date)
            return value.toISOString();
        if (value instanceof Error)
            return value.toString();
        // biome-ignore lint/suspicious/useIsArray: Intential in this context.
        if (value instanceof Array)
            return debugArray(value, depth);
        if (value instanceof Map)
            return debugMap(value, depth);
        if (value instanceof Set)
            return debugSet(value, depth);
        return debugObject(value, depth);
    }
    return typeof value;
}
/** Debug a string. */
export const debugString = (value) => `"${value.replace(ESCAPE_REGEXP, _escapeChar)}"`;
// biome-ignore lint/suspicious/noControlCharactersInRegex: Intentional.
const ESCAPE_REGEXP = /[\x00-\x08\x0B-\x1F\x7F-\x9F"\\]/g; // Match control characters, `"` double quote, `\` backslash.
const ESCAPE_LIST = {
    '"': '\\"',
    "\\": "\\\\",
    "\r": "\\r",
    "\n": "\\n",
    "\t": "\\t",
    "\b": "\\b",
    "\f": "\\f",
    "\v": "\\v",
};
const _escapeChar = (char) => ESCAPE_LIST[char] || `\\x${char.charCodeAt(0).toString(16).padStart(2, "00")}`;
/** Debug an array. */
export function debugArray(value, depth = 1) {
    const prototype = Object.getPrototypeOf(value);
    const name = prototype === Array.prototype ? "" : prototype.constructor.name || "";
    const items = depth > 0 && value.length ? value.map(v => debug(v, depth - 1)).join(",\n\t") : "";
    return `${name ? `${name} ` : ""}${value.length ? `[\n\t${items}\n]` : "[]"}`;
}
/** Debug a set. */
export function debugSet(value, depth = 1) {
    const prototype = Object.getPrototypeOf(value);
    const name = prototype === Set.prototype ? "" : prototype.constructor.name || "Set";
    const items = depth > 0 && value.size
        ? Array.from(value)
            .map(v => debug(v, depth - 1))
            .join(",\n\t")
        : "";
    return `${name}(value.size) ${items ? `{\n\t${items}\n}` : "{}"}`;
}
/** Debug a map. */
export function debugMap(value, depth = 1) {
    const prototype = Object.getPrototypeOf(value);
    const name = prototype === Map.prototype ? "" : prototype.constructor.name || "Map";
    const entries = depth > 0 && value.size
        ? Array.from(value)
            .map(([k, v]) => `${debug(k)}: ${debug(v, depth - 1)}`)
            .join(",\n\t")
        : "";
    return `${name}(value.size) ${entries ? `{\n\t${entries}\n}` : "{}"}`;
}
/** Debug an object. */
export function debugObject(value, depth = 1) {
    const prototype = Object.getPrototypeOf(value);
    const name = prototype === Object.prototype ? "" : prototype.constructor.name || "";
    const entries = depth > 0
        ? Object.entries(value)
            .map(([k, v]) => `${debug(k)}: ${debug(v, depth - 1)}`)
            .join(",\n\t")
        : "";
    return `${name ? `${name} ` : ""}${entries ? `{\n\t${entries}\n}` : "{}"}`;
}
/** If a string is multiline, push it onto the next line and prepend a tab to each line.. */
export function indent(str) {
    const lines = str.split("\n");
    return lines.length > 1 ? `\n${lines.join("\n\t")}` : ` ${str}`;
}