#API Compatibility & Standards Compliance

This document catalogs every API in qjs-modules and its relationship to established standards.

#Goals

1. Be the standard library QuickJS deserves - WHATWG-spec'd web APIs and Deno/Bun-like runtime APIs
2. Compatibility layer - scripts from browser, Node, Deno, Bun should execute with minimal changes
3. No qjs-modules-isms - avoid custom APIs that lock users into this implementation
4. Standards first - prefer WHATWG > Browser > Bun > Node > Deno when implementing similar functionality

#Classification

• Standard - Matches a published spec (WHATWG, W3C, ECMA-262, Node.js, Bun.js)
• Compatible - Similar to a standard but with minor differences
• Custom - qjs-modules specific API with no standard equivalent
• Internal - Private implementation detail, not part of public API surface
• Deprecated - Should be removed or replaced with standard alternative

#Research Status

This document is being actively researched. Agents are currently inventorying:

• All C native module exports (quickjs-*.c)
• All JS module exports (lib/*.js)

Results will be populated below as research completes.

#C Native Modules

#quickjs-archive.c

Module: archive Classification: Custom (libarchive wrapper) Spec: https://github.com/libarchive/libarchive/wiki/ManPageLibarchiveFormats3 Exports:

• Archive class - Read/write compressed archives (tar, zip, cpio, etc.)
• ArchiveEntry class - Entry metadata
• ArchiveMatch class - Pattern matching for entries

Notes: Wraps libarchive for reading/writing compressed archive formats. Not a standard API, but follows established archive format specifications. Useful for file management and distribution.

#quickjs-arraybuffer-sink.c

Module: arraybuffer-sink Classification: Custom (internal utility) Exports:

• ArrayBufferSink class - Writable buffer sink backed by resizable ArrayBuffer

Notes: Internal utility for accumulating written bytes. Used by other modules for buffer management.

#quickjs-bcrypt.c

Module: bcrypt Status: Researching...

#quickjs-bjson.c

Module: bjson Status: Researching...

#quickjs-blob.c

Module: blob Classification: Standard (WHATWG) Spec: https://w3c.github.io/FileAPI/#blob-section Exports:

• Blob class - Binary large object container
• Blob.prototype.size - Size in bytes
• Blob.prototype.type - MIME type
• Blob.prototype.slice(start, end, type) - Returns a new Blob
• Blob.prototype.text() - Returns Promise<string>
• Blob.prototype.arrayBuffer() - Returns Promise<ArrayBuffer>
• Blob.prototype.stream() - Returns ReadableStream (implemented 2026-08-12)

Browser Compatibility: Chrome 5+, Firefox 4+, Safari 5.1+, Edge 12+ Notes: Fully implements WHATWG File API spec. The stream() method was recently fixed to return a proper ReadableStream.

#quickjs-child-process.c

Module: child-process Status: Researching...

#quickjs-deep.c

Module: deep Classification: Internal Exports:

• deep.equal(a, b) - Deep equality comparison
• deep.clone(value) - Deep clone object
• deep.merge(target, source) - Deep merge objects
• deep.diff(a, b) - Compute differences
• deep.patch(target, patch) - Apply diff patch

Notes: Internal implementation detail used by lib/deep.js and test infrastructure. Provides low-level deep comparison and cloning. Not intended for direct use in user code - use lib/deep.js wrapper instead.

#quickjs-directory.c

Module: directory Status: Researching...

#quickjs-gpio.c

Module: gpio Status: Researching...

#quickjs-inspect.c

Module: inspect Classification: Compatible (Node.js util.inspect) Spec: https://nodejs.org/api/util.html#utilinspectobject-options Exports:

• inspect(value, options) - Format value for display
• inspect(value, depth) - Format with depth limit
• inspect.compact - Control whitespace (positive = entry limit, negative = leaf-relative compaction)
• inspect.colors - Enable/disable ANSI colors
• inspect.maxArrayLength - Limit array display
• inspect.maxStringLength - Limit string display
• inspect.depth - Recursion depth limit
• inspect.getters - Show getter values
• inspect.showHidden - Show non-enumerable properties
• inspect.custom - Symbol for custom inspect methods

Runtime Compatibility: Node.js util.inspect Notes: Enhanced Node.js util.inspect with negative compact values for leaf-relative object compaction (see doc/native/inspect.md). Used by console.dir() and deep.equal() for formatting.

#quickjs-internal.c

Module: internal Classification: Internal Exports:

• Module class - JavaScript module introspection
• getBytecode(func) - Get compiled bytecode
• getOpcodes() - List QuickJS opcodes

Notes: Internal implementation detail for module system introspection and bytecode inspection. Not part of public API surface. Used by qjsm (QuickJS Manager) for module management. Should not be exposed to user code in production.

#quickjs-json.c

Module: json Status: Researching...

#quickjs-lexer.c

Module: lexer Status: Researching...

#quickjs-list.c

Module: list Status: Researching...

#quickjs-location.c

Module: location Status: Researching...

#quickjs-magic.c

Module: magic Status: Researching...

#quickjs-misc.c

Module: misc Status: Researching...

#quickjs-mmap.c

Module: mmap Status: Researching...

#quickjs-mysql.c

Module: mysql Status: Researching...

#quickjs-path.c

Module: path Status: Researching...

#quickjs-pgsql.c

Module: pgsql Status: Researching...

#quickjs-pointer.c

Module: pointer Status: Researching...

#quickjs-predicate.c

Module: predicate Status: Researching...

#quickjs-queue.c

Module: queue Status: Researching...

#quickjs-repeater.c

Module: repeater Status: Researching...

#quickjs-serial.c

Module: serial Status: Researching...

#quickjs-sockets.c

Module: sockets Status: Researching...

#quickjs-sqlite.c

Module: sqlite Status: Researching...

#quickjs-stream.c

Module: stream Classification: Standard (WHATWG) Spec: https://streams.spec.whatwg.org/ Exports:

• ReadableStream class - Asynchronous data source
• WritableStream class - Asynchronous data sink
• TransformStream class - Readable + Writable pair
• ByteLengthQueuingStrategy - Queue based on byte length
• CountQueuingStrategy - Queue based on chunk count

Browser Compatibility: Chrome 52+, Firefox 65+, Safari 10.1+, Edge 16+ Notes: Implements core WHATWG Streams spec. Missing: respondWithNewView() safety checks for BYOB (Bring Your Own Buffer) readers - this is a known spec compliance gap tracked in TODO Tier 3.

#quickjs-syscallerror.c

Module: syscallerror Status: Researching...

#quickjs-textcode.c

Module: textcode Status: Researching...

#quickjs-tree-walker.c

Module: tree-walker Status: Researching...

#quickjs-virtual.c

Module: virtual Status: Researching...

#quickjs-xml.c

Module: xml Status: Researching...

#JavaScript Modules

#lib/abort.js

Module: abort Status: Researching...

#lib/arrayLike.js

Module: arrayLike Status: Researching...

#lib/assert.js

Module: assert Classification: Compatible (Node.js) Spec: https://nodejs.org/api/assert.html Exports:

• assert(value, message) - Truthiness assertion
• assert.ok(value, message) - Truthiness assertion
• assert.equal(actual, expected, message) - Loose equality
• assert.notEqual(actual, expected, message) - Loose inequality
• assert.strictEqual(actual, expected, message) - Strict equality
• assert.notStrictEqual(actual, expected, message) - Strict inequality
• assert.deepEqual(actual, expected, message) - Deep loose equality
• assert.notDeepEqual(actual, expected, message) - Deep loose inequality
• assert.deepStrictEqual(actual, expected, message) - Deep strict equality
• assert.notDeepStrictEqual(actual, expected, message) - Deep strict inequality
• assert.throws(fn, error, message) - Expect exception
• assert.doesNotThrow(fn, error, message) - Expect no exception
• assert.rejects(asyncFn, error, message) - Expect promise rejection
• assert.doesNotReject(asyncFn, error, message) - Expect no rejection
• assert.ifError(value) - Throw if truthy
• assert.fail(message) - Always fail
• assert.match(string, regexp, message) - RegExp match
• assert.doesNotMatch(string, regexp, message) - RegExp non-match

Runtime Compatibility: Node.js, Bun, Deno Notes: Comprehensive Node.js assert API. Used extensively in test suite.

#lib/asyncIterator.js

Module: asyncIterator Status: Researching...

#lib/console.js

Module: console Classification: Standard (WHATWG) Spec: https://console.spec.whatwg.org/ Exports:

• console.log(...args) - Log message
• console.error(...args) - Log error
• console.warn(...args) - Log warning
• console.info(...args) - Log info
• console.debug(...args) - Log debug
• console.dir(obj, options) - Inspect object
• console.time(label) - Start timer
• console.timeEnd(label) - End timer
• console.trace(...args) - Stack trace
• console.assert(condition, ...args) - Assertion
• console.table(data) - Table format
• console.group(label) - Group logs
• console.groupEnd() - End group

Browser Compatibility: Universal Notes: Implements core WHATWG Console API. Uses inspect module for console.dir() formatting.

#lib/css-selectors.js

Module: css-selectors Status: Researching...

#lib/css3-selectors.js

Module: css3-selectors Status: Researching...

#lib/database.js

Module: database Status: Researching...

#lib/db.js

Module: db Status: Researching...

#lib/dbi.js

Module: dbi Status: Researching...

#lib/deep.js

Module: deep Status: Researching...

#lib/describe-class.js

Module: describe-class Status: Researching...

#lib/dom.js

Module: dom Classification: Standard (W3C) Spec: https://dom.spec.whatwg.org/ Exports:

• Document class - HTML/XML document
• Element class - DOM element
• Node class - Base DOM node
• NodeList class - Collection of nodes
• HTMLCollection class - Live collection of elements
• Event class - DOM event
• EventTarget class - Event dispatch base
• HTMLElement + 50+ subclasses (Input, Button, Form, etc.)
• MutationObserver class - DOM mutation tracking
• Range class - Document range selection
• Selection class - User selection
• DOMRect class - Element geometry
• History class - Browser history API
• Navigator class - Browser environment info
• Location class - URL/location API
• Storage class - localStorage/sessionStorage
• Window class - Global window object
• File class - File API (in lib/file.js)
• DOMStringMap class - dataset API
• CSSStyleDeclaration class - Inline styles

Browser Compatibility: Universal (DOM Level 4) Notes: Comprehensive DOM implementation covering 90%+ of browser DOM APIs. See TODO Tier 9 for remaining gaps: Fetch API, FormData, CSSOM, IntersectionObserver, ResizeObserver, WebSocket, Canvas, Web Workers.

#lib/events.js

Module: events Classification: Compatible (Node.js) Spec: https://nodejs.org/api/events.html Exports:

• EventEmitter class - Event emitter base class
• EventEmitter.prototype.on(event, listener) - Add listener
• EventEmitter.prototype.once(event, listener) - Add one-time listener
• EventEmitter.prototype.off(event, listener) - Remove listener
• EventEmitter.prototype.emit(event, ...args) - Trigger event
• EventEmitter.prototype.listenerCount(event) - Count listeners

Runtime Compatibility: Node.js, Bun, Deno (with --unstable) Notes: Compatible with Node.js EventEmitter API. Different from browser EventTarget/Event API (which is in lib/dom.js). For browser-style events, use the DOM module instead.

#lib/extendArray.js

Module: extendArray Status: Researching...

#lib/extendArrayBuffer.js

Module: extendArrayBuffer Status: Researching...

#lib/extendAsyncFunction.js

Module: extendAsyncFunction Status: Researching...

#lib/extendAsyncGenerator.js

Module: extendAsyncGenerator Status: Researching...

#lib/extendFunction.js

Module: extendFunction Status: Researching...

#lib/extendGenerator.js

Module: extendGenerator Status: Researching...

#lib/extendMap.js

Module: extendMap Status: Researching...

#lib/extendMath.js

Module: extendMath Status: Researching...

#lib/extendObject.js

Module: extendObject Status: Researching...

#lib/extendSet.js

Module: extendSet Status: Researching...

#lib/file.js

Module: file Status: Researching...

#lib/fs.js

Module: fs Classification: Compatible (Node.js) Spec: https://nodejs.org/api/fs.html Exports:

• readFile(path, options, callback) - Read file async
• readFileSync(path, options) - Read file sync
• writeFile(path, data, options, callback) - Write file async
• writeFileSync(path, data, options) - Write file sync
• mkdir(path, options, callback) - Create directory
• mkdirSync(path, options) - Create directory sync
• readdir(path, options, callback) - List directory
• readdirSync(path, options) - List directory sync
• stat(path, callback) - File stats async
• statSync(path) - File stats sync
• unlink(path, callback) - Delete file
• unlinkSync(path) - Delete file sync
• exists(path, callback) - Check existence
• existsSync(path) - Check existence sync
• chmod(path, mode, callback) - Change permissions
• chmodSync(path, mode) - Change permissions sync
• chown(path, uid, gid, callback) - Change ownership
• chownSync(path, uid, gid) - Change ownership sync
• copyFile(src, dest, callback) - Copy file
• copyFileSync(src, dest) - Copy file sync
• rename(oldPath, newPath, callback) - Rename file
• renameSync(oldPath, newPath) - Rename file sync
• link(existingPath, newPath, callback) - Create hard link
• linkSync(existingPath, newPath) - Create hard link sync
• symlink(target, path, callback) - Create symlink
• symlinkSync(target, path) - Create symlink sync
• readlink(path, callback) - Read symlink
• readlinkSync(path) - Read symlink sync
• realpath(path, callback) - Resolve path
• realpathSync(path) - Resolve path sync
• truncate(path, len, callback) - Truncate file
• truncateSync(path, len) - Truncate file sync
• open(path, flags, mode, callback) - Open file
• openSync(path, flags, mode) - Open file sync
• close(fd, callback) - Close file
• closeSync(fd) - Close file sync
• read(fd, buffer, offset, length, position, callback) - Read from fd
• readSync(fd, buffer, offset, length, position) - Read from fd sync
• write(fd, buffer, offset, length, position, callback) - Write to fd
• writeSync(fd, buffer, offset, length, position) - Write to fd sync
• fstat(fd, callback) - File stats by fd
• fstatSync(fd) - File stats by fd sync
• ftruncate(fd, len, callback) - Truncate by fd
• ftruncateSync(fd, len) - Truncate by fd sync
• watch(filename, options, listener) - Watch file
• watchFile(filename, options, listener) - Watch file (polling)
• unwatchFile(filename, listener) - Stop watching
• createReadStream(path, options) - Create read stream
• createWriteStream(path, options) - Create write stream
• promises - Promise-based API (see fsPromises.js)

Runtime Compatibility: Node.js, Bun, Deno (with --unstable) Notes: Comprehensive Node.js fs API implementation. Uses quickjs-fs.c native bindings. Some advanced features (watch, streams) may have limitations vs Node.js.

#lib/fsPromises.js

Module: fsPromises Classification: Compatible (Node.js) Spec: https://nodejs.org/api/fs.html#fs_promises_api Exports:

• fsPromises.readFile(path, options) - Read file (Promise)
• fsPromises.writeFile(path, data, options) - Write file (Promise)
• fsPromises.appendFile(path, data, options) - Append to file (Promise)
• fsPromises.mkdir(path, options) - Create directory (Promise)
• fsPromises.readdir(path, options) - List directory (Promise)
• fsPromises.stat(path) - File stats (Promise)
• fsPromises.lstat(path) - Symlink stats (Promise)
• fsPromises.unlink(path) - Delete file (Promise)
• fsPromises.rmdir(path, options) - Remove directory (Promise)
• fsPromises.rm(path, options) - Remove file/dir (Promise)
• fsPromises.rename(oldPath, newPath) - Rename (Promise)
• fsPromises.copyFile(src, dest, mode) - Copy file (Promise)
• fsPromises.chmod(path, mode) - Change permissions (Promise)
• fsPromises.chown(path, uid, gid) - Change ownership (Promise)
• fsPromises.link(existingPath, newPath) - Create hard link (Promise)
• fsPromises.symlink(target, path, type) - Create symlink (Promise)
• fsPromises.readlink(path) - Read symlink (Promise)
• fsPromises.realpath(path, options) - Resolve path (Promise)
• fsPromises.truncate(path, len) - Truncate file (Promise)
• fsPromises.utimes(path, atime, mtime) - Change timestamps (Promise)
• fsPromises.access(path, mode) - Check access (Promise)
• fsPromises.open(path, flags, mode) - Open file handle (Promise)
• fsPromises.cp(src, dest, options) - Copy file/dir (Promise)
• fsPromises.glob(pattern, options) - Glob pattern match (Promise)
• fsPromises.watch(filename, options) - Watch file (AsyncIterator)

Runtime Compatibility: Node.js 10+, Bun, Deno (with --unstable) Notes: Promise-based fs API. Wraps lib/fs.js callback API with Promise interface.

#lib/html.js

Module: html Status: Researching...

#lib/inotify.js

Module: inotify Status: Researching...

#lib/io.js

Module: io Status: Researching...

#lib/iterator.js

Module: iterator Status: Researching...

#lib/misc.js

Module: misc Status: Researching...

#lib/module.js

Module: module Status: Researching...

#lib/parsel.js

Module: parsel Status: Researching...

#lib/parser.js

Module: parser Status: Researching...

#lib/perf_hooks.js

Module: perf_hooks Status: Researching...

#lib/pointer.js

Module: pointer Status: Researching...

#lib/predicate.js

Module: predicate Classification: Internal Exports:

• Predicate class - Type predicate for operator overloading
• Predicate.prototype.call(value) - Test value against predicate
• Predicate.prototype.and(other) - Logical AND
• Predicate.prototype.or(other) - Logical OR
• Predicate.prototype.not() - Logical NOT
• Predicate.type(typeCode) - Create type predicate
• Predicate.instance(class) - Create instanceof predicate
• Predicate.value(val) - Create equality predicate

Notes: Internal implementation detail used by lib/parser.js for cross-type operator dispatch. Enables terminalA >> terminalB syntax. Not intended for direct use in user code. See doc/js/predicate.md for implementation details.

#lib/process.js

Module: process Classification: Compatible (Node.js) Spec: https://nodejs.org/api/process.html Exports:

• process.argv - Command-line arguments
• process.argv0 - Original argv[0]
• process.env - Environment variables
• process.cwd() - Current working directory
• process.chdir(dir) - Change working directory
• process.exit(code) - Exit process
• process.exitCode - Exit code
• process.pid - Process ID
• process.ppid - Parent process ID
• process.platform - Platform string
• process.arch - Architecture string
• process.version - Node.js version (compatibility shim)
• process.versions - Version info
• process.release - Release metadata
• process.title - Process title
• process.stdout - Standard output stream
• process.stderr - Standard error stream
• process.stdin - Standard input stream
• process.nextTick(callback, ...args) - Queue callback
• process.hrtime() - High-resolution time
• process.hrtime.bigint() - High-resolution time as BigInt
• process.memoryUsage() - Memory usage stats
• process.cpuUsage() - CPU usage stats
• process.uptime() - Process uptime
• process.kill(pid, signal) - Send signal to process
• process.on(event, listener) - Add event listener
• process.once(event, listener) - Add one-time listener
• process.emit(event, ...args) - Emit event
• process.removeListener(event, listener) - Remove listener
• process.removeAllListeners(event) - Remove all listeners

Runtime Compatibility: Node.js, Bun, Deno (with --unstable) Notes: Comprehensive Node.js process API. Some features may have limitations vs Node.js (e.g., process.fork(), cluster support). The process.argv issue with -e mode has been fixed (see commit 72c0364d).

#lib/reflect.js

Module: reflect Status: Researching...

#lib/repl.js

Module: repl Status: Researching...

#lib/require.js

Module: require Status: Researching...

#lib/socklen_t.js

Module: socklen_t Status: Researching...

#lib/stack.js

Module: stack Status: Researching...

#lib/stream.js

Module: stream Status: Researching...

#lib/streams.js

Module: streams Status: Researching...

#lib/terminal.js

Module: terminal Status: Researching...

#lib/testharness.js

Module: testharness Status: Researching...

#lib/testharnessreport.js

Module: testharnessreport Status: Researching...

#lib/timers.js

Module: timers Classification: Standard (HTML5) Spec: https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html Exports:

• setTimeout(callback, delay, ...args) - Delayed execution
• clearTimeout(id) - Cancel timeout
• setInterval(callback, delay, ...args) - Repeated execution
• clearInterval(id) - Cancel interval
• setImmediate(callback, ...args) - Immediate execution (Node.js)
• clearImmediate(id) - Cancel immediate (Node.js)
• queueMicrotask(callback) - Queue microtask

Browser Compatibility: Universal Notes: Implements HTML5 Timers API. Also includes Node.js-style setImmediate for compatibility.

#lib/tree_walker.js

Module: tree_walker Status: Researching...

#lib/tty.js

Module: tty Status: Researching...

#lib/url.js

Module: url Classification: Standard (WHATWG) Spec: https://url.spec.whatwg.org/ Exports:

• URL class - URL parser and serializer
• URL.prototype.href - Full URL string
• URL.prototype.origin - Origin (scheme + host + port)
• URL.prototype.protocol - URL scheme
• URL.prototype.host - Host + port
• URL.prototype.hostname - Host without port
• URL.prototype.port - Port number
• URL.prototype.pathname - Path component
• URL.prototype.search - Query string
• URL.prototype.searchParams - URLSearchParams object
• URL.prototype.hash - Fragment identifier
• URLSearchParams class - Query string parser
• URL.createObjectURL(blob) - Create object URL (not yet implemented)
• URL.revokeObjectURL(url) - Revoke object URL (not yet implemented)

Browser Compatibility: Chrome 32+, Firefox 19+, Safari 7+, Edge 12+ Notes: Core URL parsing is implemented. Missing: createObjectURL() and revokeObjectURL() for Blob/File references (tracked in TODO Tier 9.6).

#lib/util.js

Module: util Status: Researching...

#lib/vfs.js

Module: vfs Status: Researching...

#lib/xml.js

Module: xml Status: Researching...

#lib/xpath.js

Module: xpath Status: Researching...

#Roadmap

Once research is complete, prioritize:

1. Deprecate custom APIs that have standard equivalents
2. Fix incompatible APIs to match standards more closely
3. Document gaps where standards exist but aren't implemented
4. Keep internal APIs that are implementation details (predicate, deep, etc.)
5. Stop adding non-standard APIs unless absolutely necessary

#Notes

• APIs like deep and predicate are internal implementation details used by other modules
• inspect is similar to Node.js util.inspect but with additional features (negative compact values)
• stream module implements WHATWG Streams spec
• blob module implements WHATWG Blob spec
• dom module implements W3C DOM spec