WordPress/Sniffs/WP/EnqueuedResourceParametersSniff.php
protected function is_falsy( $start, $end ) {

		// Find anything excluding the false tokens.
		$has_non_false = $this->phpcsFile->findNext( $this->false_tokens, $start, ( $end + 1 ), true );
		// If no non-false tokens are found, we are good.
		if ( false === $has_non_false ) {
			return true;
		}

		$code_string = '';
		for ( $i = $start; $i <= $end; $i++ ) {
			if ( isset( $this->safe_tokens[ $this->tokens[ $i ]['code'] ] ) === false ) {
				// Function call/variable or other token which makes it neigh impossible
				// to determine whether the actual value would evaluate to false.
				return false;
			}

			if ( isset( Tokens::$emptyTokens[ $this->tokens[ $i ]['code'] ] ) === true ) {
				continue;
			}

			$code_string .= $this->tokens[ $i ]['content'];
		}

		if ( '' === $code_string ) {
			return false;
		}

		// Evaluate the argument to figure out the outcome is false or not.
		// phpcs:ignore Squiz.PHP.Eval -- No harm here.
		return ( false === eval( "return (bool) $code_string;" ) );
	}
protected function is_falsy( $start, $end ) {

		// Find anything excluding the false tokens.
		$has_non_false = $this->phpcsFile->findNext( $this->false_tokens, $start, ( $end + 1 ), true );
		// If no non-false tokens are found, we are good.
		if ( false === $has_non_false ) {
			return true;
		}

		$code_string = '';
		for ( $i = $start; $i <= $end; $i++ ) {
			if ( isset( $this->safe_tokens[ $this->tokens[ $i ]['code'] ] ) === false ) {
				// Function call/variable or other token which makes it neigh impossible
				// to determine whether the actual value would evaluate to false.
				return false;
			}

			if ( isset( Tokens::$emptyTokens[ $this->tokens[ $i ]['code'] ] ) === true ) {
				continue;
			}

			$code_string .= $this->tokens[ $i ]['content'];
		}

		if ( '' === $code_string ) {
			return false;
		}

		// Evaluate the argument to figure out the outcome is false or not.
		// phpcs:ignore Squiz.PHP.Eval -- No harm here.
		return ( false === eval( "return (bool) $code_string;" ) );
	}
Determine if a range has a falsy value.

@param int $start The position to start looking from.
@param int $end   The position to stop looking (inclusive).

@return bool True if the parameter is falsy.
False if the parameter is not falsy or when it
couldn't be reliably determined.