material-components_material-components-ios/scripts/objc_diff_xml_to_md

#!/usr/bin/php
<?php

$xml = file_get_contents('php://stdin');

define(BASE_URL, 'https://github.com/google/material-components-ios');

$structure = simplexml_load_string($xml);

// http://stackoverflow.com/a/10473026
function startsWith($haystack, $needle) {
  return $needle === "" || strrpos($haystack, $needle, -strlen($haystack)) !== false;
}

$typeToSymbol = array(
  'removal' => '[deleted]',
  'addition' => '[new]',
  'modification' => '[modified]'
);

$typeToPastTenseVerb = array(
  'removal' => 'removed',
  'addition' => 'added',
  'modification' => 'modified'
);

$typeToCommit = array(
  'removal' => $argv[1],
  'addition' => $argv[2],
  'modification' => $argv[1]
);

$output = array();

function getModificationWithType($modifications, $type) {
  foreach ($modifications as $modification) {
    if ($modification->type == $type) {
      return $modification;
    }
  }
  return false;
}

function getRemovedAndAddedFromArrays($previous, $current) {
  $removed = array_filter(array_diff($previous, $current));
  $added = array_filter(array_diff($current, $previous));
  return array($removed, $added);
}

if (!empty($structure)) {
  foreach ($structure->difference as $delta) {
    if (startsWith($delta->path, '..') || startsWith(strtolower($delta->path), 'private')) {
      // Ignore source not in this component and source that is private
      continue;
    }

    $type = $typeToSymbol[strval($delta->type)];
    $verb = $typeToPastTenseVerb[strval($delta->type)];
    $commit = $typeToCommit[strval($delta->type)];
    $url = BASE_URL."/blob/$commit/".$argv[3].'/'.$delta->path.'#L'.$delta->lineNumber;
    $link = "[`".$delta->name."`]($url)";

    $lines = array();

    if ($delta->type == 'modification') {
      $modifications = $delta->modifications->modification;
      $types = array();
      foreach ($modifications as $modification) {
        $types []= $modification->type;
      }

      $oldurl = BASE_URL."/blob/".$argv[1]."/".$argv[3].'/'.$delta->path.'#L'.$delta->lineNumber;
      $newurl = BASE_URL."/blob/".$argv[2]."/".$argv[3].'/'.$delta->path.'#L'.$delta->lineNumber;

      $didOutputLines = false;

      // Special-case interpretations of modifications.
      if (count(array_diff($types, array('availability', 'deprecationMessage'))) == 0) {
        $availability = getModificationWithType($modifications, 'availability');
        $message = getModificationWithType($modifications, 'deprecationMessage');

        if ($availability->currentValue == 'Deprecated') {
          // API is newly-deprecated.
          $lines []= "- [deprecated] [`".$delta->name."`]($newurl).";
          $lines []= "*$message->currentValue*";
          $didOutputLines = true;
        }

      } else if (count(array_diff($types, array('protocols'))) == 0) {
        $protocols = getModificationWithType($modifications, 'protocols');
        list($removed, $added) = getRemovedAndAddedFromArrays(
          explode(", ", $protocols->previousValue),
          explode(", ", $protocols->currentValue));

        $lines []= "- [protocols changed] [`".$delta->name."`]($newurl).";
        if (!empty($removed)) {
          $lines []= "Removed *".implode(", ", $removed)."*.";
        }
        if (!empty($added)) {
          $lines []= "Added *".implode(", ", $added)."*.";
        }
        $didOutputLines = true;

      } else if (count(array_diff($types, array('declaration'))) == 0) {
        $declaration = getModificationWithType($modifications, 'declaration');

        if (preg_match("/@property \((.+?)\) (.+?) (.+)/", $declaration->previousValue, $previous)
        && preg_match("/@property \((.+?)\) (.+?) (.+)/", $declaration->currentValue, $current)) {
          if ($previous[2] == $current[2]) { // Same type.
            $previousAttributes = explode(", ", $previous[1]);
            $currentAttributes = explode(", ", $current[1]);
            list($removed, $added) = getRemovedAndAddedFromArrays($previousAttributes, $currentAttributes);

            $lines []= "- [property attribute change] [`".$delta->name."`]($newurl).";
            if (!empty($removed)) {
              $lines []= "Removed *".implode(", ", $removed)."*.";
            }
            if (!empty($added)) {
              $lines []= "Added *".implode(", ", $added)."*.";
            }
            $didOutputLines = true;
          }
        }
      }

      if (!$didOutputLines) {
        $lines []= "- $type $link";
        $lines []= "";
        $lines []= "| From | To | Kind |";
        $lines []= "|:---- |:-- |:---- |";

        foreach ($modifications as $modification) {
          $lines []= "| `". $modification->previousValue ."` | `". $modification->currentValue ."` | `".$modification->type ."` |";
        }
        $lines []= "";
      }

    } else {
      $lines = array("- $type $link");
    }

    $output []= $lines;
  }
}

if (empty($output)) {
  echo "No public API changes detected.\n";
  exit(0);
}

$firstlines = array();
foreach ($output as $lines) {
  $firstlines []= $lines[0];
}

array_multisort($output, $firstlines);

foreach ($output as $lines) {
  echo implode("\n", $lines)."\n";
}

?>