diff --git a/components/DataLiberation/class-javascript-tokenizer.php b/components/DataLiberation/class-javascript-tokenizer.php
new file mode 100644
index 00000000..6d0f0999
--- /dev/null
+++ b/components/DataLiberation/class-javascript-tokenizer.php
@@ -0,0 +1,595 @@
+<?php
+
+namespace WordPress\DataLiberation;
+
+/**
+ * First stab at tokenizing JavaScript according to the language specification at:
+ *
+ * https://tc39.es/ecma262/#sec-unicode-format-control-characters
+ * 
+ * It parses the source into subatomic particles, that is tokens that are more fine-grained
+ * than you might expect. Consider this fragment:
+ * 
+ *     const \u{0061}mazing = 'yes';
+ * 
+ * A more advanced tokenizer could yield the following non-whitespace tokens:
+ * 
+ *     `const`, `amazing`, `=`, `'yes'`
+ * 
+ * This tokenizer, however, will yield the following non-whitespace tokens:
+ * 
+ *     `const`, `\u`, `{`, `0061`, `}`, `mazing`, `=`, `'yes'`
+ * 
+ * There are a few shortcomings as well:
+ * 
+ * * Line separator and paragraph separator are not recognized as line terminators.
+ * * ... more to discover :-)...
+ */
+class JavaScriptTokenizer {
+
+	const T_SINGLE_LINE_COMMENT = 'SingleLineComment';
+	const T_MULTI_LINE_COMMENT = 'MultiLineComment';
+	const T_REGEX_LITERAL = 'RegularExpressionLiteral';
+	const T_STRING_LITERAL = 'StringLiteral';
+	const T_NO_SUBST_TEMPLATE = 'NoSubstitutionTemplate';
+	const T_TEMPLATE_HEAD = 'TemplateHead';
+	const T_TEMPLATE_MIDDLE = 'TemplateMiddle';
+	const T_TEMPLATE_TAIL = 'TemplateTail';
+	const T_NUMERIC_LITERAL = 'NumericLiteral';
+	const T_PUNCTUATOR = 'Punctuator';
+	const T_IDENTIFIER_NAME = 'IdentifierName';
+	const T_PRIVATE_IDENTIFIER = 'PrivateIdentifier';
+
+	// Whitespace chars: space, tab, LF, CR.
+	const WS = " \t\n\r";
+
+	// Characters that start "punctuators" or terminate identifiers.
+	const NON_IDENT = " \t\r\n!%^&*()-=+[]{}|;:~,./<>?`\"'";
+
+	private $keywords = array(
+		'await' => true,
+		'case' => true,
+		'delete' => true,
+		'in' => true,
+		'instanceof' => true,
+		'return' => true,
+		'throw' => true,
+		'typeof' => true,
+		'void' => true,
+		'yield' => true,
+		'!' => true,
+		'!==' => true,
+		'%' => true,
+		'%=' => true,
+		'^' => true,
+		'^=' => true,
+		'&' => true,
+		'&=' => true,
+		'&&' => true,
+		'&&=' => true,
+		'*' => true,
+		'*=' => true,
+		'**' => true,
+		'**=' => true,
+		'(' => true,
+		'-' => true,
+		'-=' => true,
+		'=' => true,
+		'==' => true,
+		'===' => true,
+		'=>' => true,
+		'+' => true,
+		'+=' => true,
+		'[' => true,
+		'{' => true,
+		'}' => true,
+		'|' => true,
+		'|=' => true,
+		'||' => true,
+		'||=' => true,
+		';' => true,
+		':' => true,
+		'~' => true,
+		',' => true,
+		'...' => true,
+		'/' => true,
+		'/=' => true,
+		'<' => true,
+		'<=' => true,
+		'<<' => true,
+		'<<=' => true,
+		'>' => true,
+		'>=' => true,
+		'>>' => true,
+		'>>=' => true,
+		'>>>' => true,
+		'>>>=' => true,
+		'?' => true,
+		'??' => true,
+		'??=' => true,
+		self::T_TEMPLATE_HEAD => true,
+		self::T_TEMPLATE_MIDDLE => true
+	);
+
+	/** @var string */
+	private $js = '';
+
+	/** @var int */
+	private $bytes_parsed_so_far = 0;
+
+	/** @var int */
+	private $level = 1;
+
+	/** @var int */
+	private $levels = 0;
+
+	/** @var string */
+	private $last_token = ';';
+
+	/** @var string|null */
+	private $token_type = null;
+
+	/** @var int|null */
+	private $token_start = null;
+
+	/** @var int|null */
+	private $token_end = null;
+
+	public function __construct( string $code ) {
+		$this->js = $code;
+	}
+
+	/** Returns true if a token was read, false on EOF. */
+	public function next_token() {
+		// Skip whitespace.
+		$this->bytes_parsed_so_far += strspn( $this->js, self::WS, $this->bytes_parsed_so_far );
+
+		if ( $this->bytes_parsed_so_far >= strlen( $this->js ) ) {
+			$this->token_type = '';
+
+			return false;
+		}
+
+		$byte = $this->js[ $this->bytes_parsed_so_far ];
+
+		// Comments and possible regex literal start with '/'.
+		if ( '/' === $byte ) {
+			$next = ( $this->bytes_parsed_so_far + 1 < strlen( $this->js ) ) ? $this->js[ $this->bytes_parsed_so_far + 1 ] : '';
+
+			if ( '/' === $next ) {
+				$this->token_start = $this->bytes_parsed_so_far;
+				// Consume the next line of text
+				$this->bytes_parsed_so_far += strcspn( $this->js, "\r\n", $this->bytes_parsed_so_far );
+				// Line separator and paragraph separator are not supported as line terminators at the moment.
+				
+				$this->token_type  = self::T_SINGLE_LINE_COMMENT;
+				$this->token_end   = $this->bytes_parsed_so_far;
+
+				// Comments don't affect $last_token.
+				return true;
+			}
+
+			if ( '*' === $next ) {
+				$this->token_start         = $this->bytes_parsed_so_far;
+				$end                       = strpos( $this->js, '*/', $this->bytes_parsed_so_far + 2 );
+				$this->bytes_parsed_so_far = ( false === $end ) ? strlen( $this->js ) : $end + 2;
+				$this->token_type          = self::T_MULTI_LINE_COMMENT;
+				$this->token_end           = $this->bytes_parsed_so_far;
+
+				return true;
+			}
+
+			if ( isset( $this->keywords[ $this->last_token ] ) ) {
+				$this->token_start = $this->bytes_parsed_so_far;
+				++ $this->bytes_parsed_so_far; // past initial '/'
+				// Consume the regular expression
+				while ( $this->bytes_parsed_so_far < strlen( $this->js ) ) {
+					$next = strpos( $this->js, '/', $this->bytes_parsed_so_far );
+					if ( false === $next ) {
+						$this->bytes_parsed_so_far = strlen( $this->js );
+						break;
+					}
+					if ( $this->is_escaped( $next ) ) {
+						$this->bytes_parsed_so_far = $next + 1;
+						continue;
+					}
+					$this->bytes_parsed_so_far = $next + 1; // past closing '/'; now flags
+					break;
+				}
+				// @TODO: Why dgimsuy?
+				$this->bytes_parsed_so_far += strspn( $this->js, 'dgimsuy', $this->bytes_parsed_so_far );
+				$this->token_type = self::T_REGEX_LITERAL;
+				$this->token_end  = $this->bytes_parsed_so_far;
+
+				// Intentionally do not change $last_token (matches source behavior).
+				return true;
+			}
+		}
+
+		// String literals.
+		if ( '\'' === $byte || '"' === $byte ) {
+			$this->token_start = $this->bytes_parsed_so_far;
+			++ $this->bytes_parsed_so_far; // skip opening quote
+			
+			// Consume the string literal
+			$quote = $byte;
+			while ( $this->bytes_parsed_so_far < strlen( $this->js ) ) {
+				$next = strpos( $this->js, $quote, $this->bytes_parsed_so_far );
+				if ( false === $next ) {
+					$this->bytes_parsed_so_far = strlen( $this->js );
+
+					break;
+				}
+				// If the quote is escaped, skip it and continue.
+				if ( $this->is_escaped( $next ) ) {
+					$this->bytes_parsed_so_far = $next + 1;
+					continue;
+				}
+				$this->bytes_parsed_so_far = $next + 1;
+
+				break;
+			}
+			
+			$this->token_type  = self::T_STRING_LITERAL;
+			$this->token_end   = $this->bytes_parsed_so_far;
+			$this->last_token  = self::T_STRING_LITERAL;
+
+			return true;
+		}
+
+		// Template literals.
+		if ( '`' === $byte ) {
+			$this->token_start = $this->bytes_parsed_so_far;
+			++ $this->bytes_parsed_so_far; // skip `
+			while ( $this->bytes_parsed_so_far < strlen( $this->js ) ) {
+				// Fast skip to next potential stop: ` $ or \.
+				$this->bytes_parsed_so_far += strcspn( $this->js, '`$\\', $this->bytes_parsed_so_far );
+
+				if ( $this->bytes_parsed_so_far >= strlen( $this->js ) ) {
+					break;
+				}
+
+				$byte = $this->js[ $this->bytes_parsed_so_far ];
+
+				// Handle backslash escapes.
+				if ( '\\' === $byte ) {
+					// Skip escaped character (skip \ and next char).
+					$this->bytes_parsed_so_far += ( $this->bytes_parsed_so_far + 1 < strlen( $this->js ) ) ? 2 : 1;
+					continue;
+				}
+
+				// Check for backtick.
+				if ( '`' === $byte ) {
+					++ $this->bytes_parsed_so_far;
+					$this->token_type = self::T_NO_SUBST_TEMPLATE;
+					$this->token_end  = $this->bytes_parsed_so_far;
+					$this->last_token = self::T_NO_SUBST_TEMPLATE;
+
+					return true;
+				}
+
+				// Check for ${.
+				if ( '$' === $byte && $this->bytes_parsed_so_far + 1 < strlen( $this->js ) && '{' === $this->js[ $this->bytes_parsed_so_far + 1 ] ) {
+					++ $this->level;
+					++ $this->levels;
+					$this->bytes_parsed_so_far += 2; // past ${
+					$this->token_type          = self::T_TEMPLATE_HEAD;
+					$this->token_end           = $this->bytes_parsed_so_far;
+					$this->last_token          = self::T_TEMPLATE_HEAD;
+
+					return true;
+				}
+
+				// Just a plain $, keep scanning.
+				++ $this->bytes_parsed_so_far;
+			}
+			// Unterminated: treat what we saw as a no-subst template anyway.
+			$this->token_type = self::T_NO_SUBST_TEMPLATE;
+			$this->token_end  = $this->bytes_parsed_so_far;
+			$this->last_token = self::T_NO_SUBST_TEMPLATE;
+
+			return true;
+		}
+
+		// Numbers.
+		$before = $this->bytes_parsed_so_far;
+		$this->consume_number();
+		if ( $this->bytes_parsed_so_far !== $before ) {
+			$this->token_type  = self::T_NUMERIC_LITERAL;
+			$this->token_start = $before;
+			$this->token_end   = $this->bytes_parsed_so_far;
+			$this->last_token  = self::T_NUMERIC_LITERAL;
+
+			return true;
+		}
+
+		// Punctuators.
+		$punct = $this->parse_punctuator();
+		if ( '' !== $punct ) {
+			$at                     = $this->bytes_parsed_so_far;
+			$this->bytes_parsed_so_far += strlen( $punct );
+			$this->last_token          = $punct;
+
+			// Template expression boundary handling after '}'.
+			if ( 0 !== $this->levels ) {
+				if ( '{' === $punct ) {
+					++ $this->level;
+				} elseif ( '}' === $punct ) {
+					-- $this->level;
+					if ( $this->level === $this->levels ) {
+						-- $this->levels;
+						$this->token_start = $this->bytes_parsed_so_far - 1;
+
+						while ( $this->bytes_parsed_so_far < strlen( $this->js ) ) {
+							// Fast skip to next potential stop: ` $ or \.
+							$this->bytes_parsed_so_far += strcspn( $this->js, '`$\\', $this->bytes_parsed_so_far );
+
+							if ( $this->bytes_parsed_so_far >= strlen( $this->js ) ) {
+								break;
+							}
+
+							$ch = $this->js[ $this->bytes_parsed_so_far ];
+
+							// Handle backslash escapes.
+							if ( '\\' === $ch ) {
+								// Skip escaped character (skip \ and next char).
+								$this->bytes_parsed_so_far += ( $this->bytes_parsed_so_far + 1 < strlen( $this->js ) ) ? 2 : 1;
+								continue;
+							}
+
+							// Check for backtick.
+							if ( '`' === $ch ) {
+								++ $this->bytes_parsed_so_far;
+								$this->token_type = self::T_TEMPLATE_TAIL;
+								$this->token_end  = $this->bytes_parsed_so_far;
+								$this->last_token = self::T_TEMPLATE_TAIL;
+
+								return true;
+							}
+
+							// Check for ${.
+							if ( '$' === $ch && $this->bytes_parsed_so_far + 1 < strlen( $this->js ) && '{' === $this->js[ $this->bytes_parsed_so_far + 1 ] ) {
+								++ $this->level;
+								$this->bytes_parsed_so_far += 2; // ${
+								$this->token_type          = self::T_TEMPLATE_MIDDLE;
+								$this->token_end           = $this->bytes_parsed_so_far;
+								$this->last_token          = self::T_TEMPLATE_MIDDLE;
+
+								return true;
+							}
+
+							// Just a plain $, keep scanning.
+							++ $this->bytes_parsed_so_far;
+						}
+
+						// If unterminated, emit tail from '}' to EOF.
+						$this->token_type = self::T_TEMPLATE_TAIL;
+						$this->token_end  = $this->bytes_parsed_so_far;
+						$this->last_token = self::T_TEMPLATE_TAIL;
+
+						return true;
+					}
+				}
+			}
+
+			$this->token_type  = self::T_PUNCTUATOR;
+			$this->token_start = $at;
+			$this->token_end   = $this->bytes_parsed_so_far;
+
+			return true;
+		}
+
+		// Identifier / private identifier / unknown word-like chunk.
+		$this->token_start = $this->bytes_parsed_so_far;
+		// Fast skip until any whitespace or any punctuator-start char.
+		$this->bytes_parsed_so_far += strcspn( $this->js, self::NON_IDENT, $this->bytes_parsed_so_far );
+		$this->token_type = ( $this->token_start < strlen( $this->js ) && '#' === $this->js[ $this->token_start ] ) ? self::T_PRIVATE_IDENTIFIER : self::T_IDENTIFIER_NAME;
+		$this->token_end  = $this->bytes_parsed_so_far;
+		// Note: $last_token becomes the literal identifier text (affects regex detection).
+		$this->last_token = substr( $this->js, $this->token_start, $this->token_end - $this->token_start );
+
+		return true;
+	}
+
+	private function is_escaped( $pos ) {
+		// True if an odd number of backslashes precede position $pos.
+		$run = 0;
+		$i   = $pos - 1;
+		while ( $i >= 0 && '\\' === $this->js[ $i ] ) {
+			++ $run;
+			-- $i;
+		}
+
+		return ( $run & 1 ) === 1;
+	}
+
+	private function consume_number() {
+		$at   = $this->bytes_parsed_so_far;
+		$byte = ( $at < strlen( $this->js ) ) ? $this->js[ $at ] : '';
+
+		if ( '0' === $byte ) {
+			$n1 = ( $at + 1 < strlen( $this->js ) ) ? $this->js[ $at + 1 ] : '';
+			if ( 'b' === $n1 || 'B' === $n1 ) {
+				$at += 2;
+				$at += strspn( $this->js, '01', $at );
+
+				$this->bytes_parsed_so_far = $at;
+
+				return;
+			}
+			if ( 'x' === $n1 || 'X' === $n1 ) {
+				$at += 2;
+				$at += strspn( $this->js, '0123456789abcdefABCDEF', $at );
+
+				$this->bytes_parsed_so_far = $at;
+
+				return;
+			}
+		} elseif ( '.' === $byte ) {
+			++ $at;
+			if ( 1 !== strspn( $this->js, '0123456789', $at, 1 ) ) {
+				// Not a number; restore.
+				$this->bytes_parsed_so_far = $this->bytes_parsed_so_far; // no-op, for readability
+
+				return;
+			}
+		} elseif ( 1 !== strspn( $this->js, '0123456789', $at, 1 ) ) {
+			return;
+		}
+
+		++ $at; // consumed first digit or leading '.'
+		while ( true ) {
+			$at   += strspn( $this->js, '0123456789', $at );
+			$byte = ( $at < strlen( $this->js ) ) ? $this->js[ $at ] : "\0";
+
+			if ( '_' === $byte ) {
+				++ $at;
+				continue;
+			}
+
+			if ( 'e' === $byte || 'E' === $byte ) {
+				++ $at;
+				$sign = ( $at < strlen( $this->js ) ) ? $this->js[ $at ] : "\0";
+				if ( '+' === $sign || '-' === $sign ) {
+					++ $at;
+				}
+				$at                        += strspn( $this->js, '0123456789', $at );
+				$this->bytes_parsed_so_far = $at;
+
+				return;
+			}
+
+			if ( 'n' === $byte ) { // BigInt
+				++ $at;
+				$this->bytes_parsed_so_far = $at;
+
+				return;
+			}
+
+			if ( '.' === $byte ) {
+				++ $at;
+				continue;
+			}
+
+			$this->bytes_parsed_so_far = $at;
+
+			return;
+		}
+	}
+
+	private function parse_punctuator() {
+		$at  = $this->bytes_parsed_so_far;
+		$len = strlen( $this->js );
+		
+		if ( $at >= $len ) {
+			return '';
+		}
+
+		switch ( $this->js[ $at ] ) {
+			case '(':
+			case ')':
+			case '[':
+			case ']':
+			case '{':
+			case '}':
+			case ';':
+			case ':':
+			case '~':
+			case ',':
+				return $this->js[ $at ];
+		}
+
+		if($at + 1 >= $len) {
+			return false;
+		}
+
+		switch ( $this->js[ $at ] ) {
+			case '/':
+				return ( '=' === $this->js[ $at + 1 ] ) ? '/=' : '/';
+			case '%':
+				return ( '=' === $this->js[ $at + 1 ] ) ? '%=' : '%';
+			case '^':
+				return ( '=' === $this->js[ $at + 1 ] ) ? '^=' : '^';
+			case '!':
+				if ( '=' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '!==' : '!=';
+				}
+				return '!';
+			case '&':
+				if ( '&' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '&&=' : '&&';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '&=' : '&';
+			case '*':
+				if ( '*' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '**=' : '**';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '*=' : '*';
+			case '-':
+				if ( '-' === $this->js[ $at + 1 ] ) {
+					return '--';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '-=' : '-';
+			case '=':
+				if ( '=' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '===' : '==';
+				}
+				return ( '>' === $this->js[ $at + 1 ] ) ? '=>' : '=';
+			case '+':
+				if ( '+' === $this->js[ $at + 1 ] ) {
+					return '++';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '+=' : '+';
+			case '|':
+				if ( '|' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '||=' : '||';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '|=' : '|';
+			case '.':
+				if ( '.' === $this->js[ $at + 1 ] && $at + 2 < $len && '.' === $this->js[ $at + 2 ] ) {
+					return '...';
+				}
+				return '.';
+			case '<':
+				if ( '<' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '<<=' : '<<';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '<=' : '<';
+			case '>':
+				if ( '>' === $this->js[ $at + 1 ] ) {
+					if ( $at + 2 < $len && '>' === $this->js[ $at + 2 ] ) {
+						return ( $at + 3 < $len && '=' === $this->js[ $at + 3 ] ) ? '>>>=' : '>>>';
+					}
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '>>=' : '>>';
+				}
+				return ( '=' === $this->js[ $at + 1 ] ) ? '>=' : '>';
+			case '?':
+				if ( '?' === $this->js[ $at + 1 ] ) {
+					return ( $at + 2 < $len && '=' === $this->js[ $at + 2 ] ) ? '??=' : '??';
+				}
+				if ( '.' === $this->js[ $at + 1 ] ) {
+					return '?.';
+				}
+				return '?';
+			default:
+				return '';
+		}
+	}
+
+	public function get_type() {
+		return $this->token_type;
+	}
+
+	public function get_token_start() {
+		return $this->token_start;
+	}
+
+	public function get_token_end() {
+		return $this->token_end;
+	}
+
+	public function get_text() {
+		return substr( $this->js, $this->token_start, $this->token_end - $this->token_start );
+	}
+
+}