Issue #2752591 by quietone, mallezie, dawehner, mikeryan: Add substr process plugin

core/modules/migrate/src/Plugin/migrate/process/Substr.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Drupal\migrate\Plugin\migrate\process;
+
+use Drupal\migrate\ProcessPluginBase;
+use Drupal\migrate\MigrateExecutableInterface;
+use Drupal\migrate\Row;
+use Drupal\migrate\MigrateException;
+use Drupal\Component\Utility\Unicode;
+
+/**
+ * This plugin returns a substring of the current value.
+ *
+ * @MigrateProcessPlugin(
+ *   id = "substr"
+ * )
+ */
+class Substr extends ProcessPluginBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
+    $start = isset($this->configuration['start']) ? $this->configuration['start'] : 0;
+    if (!is_int($start)) {
+      throw new MigrateException('The start position configuration value should be an integer. Omit this key to capture from the beginning of the string.');
+    }
+    $length = isset($this->configuration['length']) ? $this->configuration['length'] : NULL;
+    if (!is_null($length) && !is_int($length)) {
+      throw new MigrateException('The character length configuration value should be an integer. Omit this key to capture from the start position to the end of the string.');
+    }
+    if (!is_string($value)) {
+      throw new MigrateException('The input value must be a string.');
+    }
+
+    // Use optional start or length to return a portion of $value.
+    $new_value = Unicode::substr($value, $start, $length);
+    return $new_value;
+  }
+
+}

core/modules/migrate/tests/src/Unit/process/SubstrTest.php

@@ -0,0 +1,92 @@
+<?php
+
+namespace Drupal\Tests\migrate\Unit\process;
+
+use Drupal\migrate\Plugin\migrate\process\Substr;
+
+/**
+ * Tests the substr plugin.
+ *
+ * @coversDefaultClass \Drupal\migrate\Plugin\migrate\process\Substr
+ *
+ * @group migrate
+ */
+class SubstrTest extends MigrateProcessTestCase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+  }
+
+  /**
+   * Tests Substr plugin based on providerTestSubstr() values.
+   *
+   * @dataProvider providerTestSubstr
+   */
+  public function testSubstr($start = NULL, $length = NULL, $expected = NULL) {
+    $configuration['start'] = $start;
+    $configuration['length'] = $length;
+    $this->plugin = new Substr($configuration, 'map', []);
+    $value = $this->plugin->transform('Captain Janeway', $this->migrateExecutable, $this->row, 'destinationproperty');
+    $this->assertSame($expected, $value);
+  }
+
+  /**
+   * Data provider for testSubstr().
+   */
+  public function providerTestSubstr() {
+    return [
+      // Tests with valid start and length values.
+      [0, 7, 'Captain'],
+      // Tests with valid start > 0 and valid length.
+      [6, 3, 'n J'],
+      // Tests with valid start < 0 and valid length.
+      [-7, 4, 'Jane'],
+      // Tests without start value and valid length value.
+      [NULL, 7, 'Captain'],
+      // Tests with valid start value and no length value.
+      [1, NULL, 'aptain Janeway'],
+      // Tests without both start and length values.
+      [NULL, NULL, 'Captain Janeway'],
+    ];
+  }
+
+  /**
+   * Tests invalid input type.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The input value must be a string.
+   */
+  public function testSubstrFail() {
+    $configuration = [];
+    $this->plugin = new Substr($configuration, 'map', []);
+    $this->plugin->transform(['Captain Janeway'], $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests that the start parameter is an integer.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The start position configuration value should be an integer. Omit this key to capture from the beginning of the string.
+   */
+  public function testStartIsString() {
+    $configuration['start'] = '2';
+    $this->plugin = new Substr($configuration, 'map', []);
+    $this->plugin->transform(['foo'], $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests that the length parameter is an integer.
+   *
+   * @expectedException \Drupal\migrate\MigrateException
+   * @expectedExceptionMessage The character length configuration value should be an integer. Omit this key to capture from the start position to the end of the string.
+   */
+  public function testLengthIsString() {
+    $configuration['length'] = '1';
+    $this->plugin = new Substr($configuration, 'map', []);
+    $this->plugin->transform(['foo'], $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+}