<?php declare(strict_types=1);
/*
* This file is part of sebastian/diff.
*
* (c) Sebastian Bergmann <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace SebastianBergmann\Diff\Output;
use function array_merge;
use function array_splice;
use function count;
use function fclose;
use function fopen;
use function fwrite;
use function is_bool;
use function is_int;
use function is_string;
use function max;
use function min;
use function sprintf;
use function stream_get_contents;
use function substr;
use SebastianBergmann\Diff\ConfigurationException;
use SebastianBergmann\Diff\Differ;
/**
* Strict Unified diff output builder.
*
* Generates (strict) Unified diff's (unidiffs) with hunks.
*/
final class StrictUnifiedDiffOutputBuilder implements DiffOutputBuilderInterface
{
private static $default = [
'collapseRanges' => true, // ranges of length one are rendered with the trailing `,1`
'commonLineThreshold' => 6, // number of same lines before ending a new hunk and creating a new one (if needed)
'contextLines' => 3, // like `diff: -u, -U NUM, --unified[=NUM]`, for patch/git apply compatibility best to keep at least @ 3
'fromFile' => null,
'fromFileDate' => null,
'toFile' => null,
'toFileDate' => null,
];
/**
* @var bool
*/
private $changed;
/**
* @var bool
*/
private $collapseRanges;
/**
* @var int >= 0
*/
private $commonLineThreshold;
/**
* @var string
*/
private $header;
/**
* @var int >= 0
*/
private $contextLines;
public function __construct(array $options = [])
{
$options = array_merge(self::$default, $options);
if (!is_bool($options['collapseRanges'])) {
throw new ConfigurationException('collapseRanges', 'a bool', $options['collapseRanges']);
}
if (!is_int($options['contextLines']) || $options['contextLines'] < 0) {
throw new ConfigurationException('contextLines', 'an int >= 0', $options['contextLines']);
}
if (!is_int($options['commonLineThreshold']) || $options['commonLineThreshold'] <= 0) {
throw new ConfigurationException('commonLineThreshold', 'an int > 0', $options['commonLineThreshold']);
}
$this->assertString($options, 'fromFile');
$this->assertString($options, 'toFile');
$this->assertStringOrNull($options, 'fromFileDate');
$this->assertStringOrNull($options, 'toFileDate');
$this->header = sprintf(
"--- %s%s\n+++ %s%s\n",
$options['fromFile'],
null === $options['fromFileDate'] ? '' : "\t" . $options['fromFileDate'],
$options['toFile'],
null === $options['toFileDate'] ? '' : "\t" . $options['toFileDate']
);
$this->collapseRanges = $options['collapseRanges'];
$this->commonLineThreshold = $options['commonLineThreshold'];
$this->contextLines = $options['contextLines'];
}
public function getDiff(array $diff): string
{
if (0 === count($diff)) {
return '';
}
$this->changed = false;
$buffer = fopen('php://memory', 'r+b');
fwrite($buffer, $this->header);
$this->writeDiffHunks($buffer, $diff);
if (!$this->changed) {
fclose($buffer);
return '';
}
$diff = stream_get_contents($buffer, -1, 0);
fclose($buffer);
// If the last char is not a linebreak: add it.
// This might happen when both the `from` and `to` do not have a trailing linebreak
$last = substr($diff, -1);
return "\n" !== $last && "\r" !== $last
? $diff . "\n"
: $diff;
}
private function writeDiffHunks($output, array $diff): void
{
// detect "No newline at end of file" and insert into `$diff` if needed
$upperLimit = count($diff);
if (0 === $diff[$upperLimit - 1][1]) {
$lc = substr($diff[$upperLimit - 1][0], -1);
if ("\n" !== $lc) {
array_splice($diff, $upperLimit, 0, [["\n\\ No newline at end of file\n", Differ::NO_LINE_END_EOF_WARNING]]);
}
} else {
// search back for the last `+` and `-` line,
// check if has trailing linebreak, else add under it warning under it
$toFind = [1 => true, 2 => true];
for ($i = $upperLimit - 1; $i >= 0; --$i) {
if (isset($toFind[$diff[$i][1]])) {
unset($toFind[$diff[$i][1]]);
$lc = substr($diff[$i][0], -1);
if ("\n" !== $lc) {
array_splice($diff, $i + 1, 0, [["\n\\ No newline at end of file\n", Differ::NO_LINE_END_EOF_WARNING]]);
}
if (!count($toFind)) {
break;
}
}
}
}
// write hunks to output buffer
$cutOff = max($this->commonLineThreshold, $this->contextLines);
$hunkCapture = false;
$sameCount = $toRange = $fromRange = 0;
$toStart = $fromStart = 1;
$i = 0;
/** @var int $i */
foreach ($diff as $i => $entry) {
if (0 === $entry[1]) { // same
if (false === $hunkCapture) {
++$fromStart;
++$toStart;
continue;
}
++$sameCount;
++$toRange;
++$fromRange;
if ($sameCount === $cutOff) {
$contextStartOffset = ($hunkCapture - $this->contextLines) < 0
? $hunkCapture
: $this->contextLines;
// note: $contextEndOffset = $this->contextLines;
//
// because we never go beyond the end of the diff.
// with the cutoff/contextlines here the follow is never true;
//
// if ($i - $cutOff + $this->contextLines + 1 > \count($diff)) {
// $contextEndOffset = count($diff) - 1;
// }
//
// ; that would be true for a trailing incomplete hunk case which is dealt with after this loop
$this->writeHunk(
$diff,
$hunkCapture - $contextStartOffset,
$i - $cutOff + $this->contextLines + 1,
$fromStart - $contextStartOffset,
$fromRange - $cutOff + $contextStartOffset + $this->contextLines,
$toStart - $contextStartOffset,
$toRange - $cutOff + $contextStartOffset + $this->contextLines,
$output
);
$fromStart += $fromRange;
$toStart += $toRange;
$hunkCapture = false;
$sameCount = $toRange = $fromRange = 0;
}
continue;
}
$sameCount = 0;
if ($entry[1] === Differ::NO_LINE_END_EOF_WARNING) {
continue;
}
$this->changed = true;
if (false === $hunkCapture) {
$hunkCapture = $i;
}
if (Differ::ADDED === $entry[1]) { // added
++$toRange;
}
if (Differ::REMOVED === $entry[1]) { // removed
++$fromRange;
}
}
if (false === $hunkCapture) {
return;
}
// we end here when cutoff (commonLineThreshold) was not reached, but we where capturing a hunk,
// do not render hunk till end automatically because the number of context lines might be less than the commonLineThreshold
$contextStartOffset = $hunkCapture - $this->contextLines < 0
? $hunkCapture
: $this->contextLines;
// prevent trying to write out more common lines than there are in the diff _and_
// do not write more than configured through the context lines
$contextEndOffset = min($sameCount, $this->contextLines);
$fromRange -= $sameCount;
$toRange -= $sameCount;
$this->writeHunk(
$diff,
$hunkCapture - $contextStartOffset,
$i - $sameCount + $contextEndOffset + 1,
$fromStart - $contextStartOffset,
$fromRange + $contextStartOffset + $contextEndOffset,
$toStart - $contextStartOffset,
$toRange + $contextStartOffset + $contextEndOffset,
$output
);
}
private function writeHunk(
array $diff,
int $diffStartIndex,
int $diffEndIndex,
int $fromStart,
int $fromRange,
int $toStart,
int $toRange,
$output
): void {
fwrite($output, '@@ -' . $fromStart);
if (!$this->collapseRanges || 1 !== $fromRange) {
fwrite($output, ',' . $fromRange);
}
fwrite($output, ' +' . $toStart);
if (!$this->collapseRanges || 1 !== $toRange) {
fwrite($output, ',' . $toRange);
}
fwrite($output, " @@\n");
for ($i = $diffStartIndex; $i < $diffEndIndex; ++$i) {
if ($diff[$i][1] === Differ::ADDED) {
$this->changed = true;
fwrite($output, '+' . $diff[$i][0]);
} elseif ($diff[$i][1] === Differ::REMOVED) {
$this->changed = true;
fwrite($output, '-' . $diff[$i][0]);
} elseif ($diff[$i][1] === Differ::OLD) {
fwrite($output, ' ' . $diff[$i][0]);
} elseif ($diff[$i][1] === Differ::NO_LINE_END_EOF_WARNING) {
$this->changed = true;
fwrite($output, $diff[$i][0]);
}
//} elseif ($diff[$i][1] === Differ::DIFF_LINE_END_WARNING) { // custom comment inserted by PHPUnit/diff package
// skip
//} else {
// unknown/invalid
//}
}
}
private function assertString(array $options, string $option): void
{
if (!is_string($options[$option])) {
throw new ConfigurationException($option, 'a string', $options[$option]);
}
}
private function assertStringOrNull(array $options, string $option): void
{
if (null !== $options[$option] && !is_string($options[$option])) {
throw new ConfigurationException($option, 'a string or <null>', $options[$option]);
}
}
}