Fix wp term migrate skipping posts after post type migration (#606)

Co-authored-by: swissspidy <841956+swissspidy@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Pascal Birchler <pascalb@google.com>

Author: Copilot

features/term-migrate.feature

@@ -87,3 +87,66 @@ Feature: Migrate term custom fields
       """
       Error: Taxonomy term 'peach' for taxonomy 'category' doesn't exist.
       """
+
+  @require-wp-4.4
+  Scenario: Migrate a term when posts have been migrated to a different post type that supports the destination taxonomy
+    Given a WP install
+    And a wp-content/mu-plugins/test-migrate.php file:
+      """
+      <?php
+      // Plugin Name: Test Migrate
+
+      add_action( 'init', function() {
+        register_post_type( 'news', [ 'public' => true ] );
+        register_taxonomy( 'topic', 'news', [ 'public' => true ] );
+      } );
+      """
+
+    When I run `wp term create category grape`
+    Then STDOUT should not be empty
+
+    When I run `wp post create --post_title='Test post' --post_type=post --porcelain`
+    Then STDOUT should be a number
+    And save STDOUT as {POST_ID}
+
+    When I run `wp post term set {POST_ID} category grape`
+    Then STDOUT should not be empty
+
+    When I run `wp post update {POST_ID} --post_type=news`
+    Then STDOUT should not be empty
+
+    When I run `wp term migrate grape --by=slug --from=category --to=topic`
+    Then STDOUT should be:
+      """
+      Term 'grape' assigned to post {POST_ID}.
+      Term 'grape' migrated.
+      Old instance of term 'grape' removed from its original taxonomy.
+      Success: Migrated the term 'grape' from taxonomy 'category' to taxonomy 'topic' for 1 post.
+      """
+
+  @require-wp-4.4
+  Scenario: Migrate a term warns when post type is not registered with destination taxonomy
+    Given a WP install
+
+    When I run `wp term create category grape`
+    Then STDOUT should not be empty
+
+    When I run `wp post create --post_title='Test post' --post_type=post --porcelain`
+    Then STDOUT should be a number
+    And save STDOUT as {POST_ID}
+
+    When I run `wp post term set {POST_ID} category grape`
+    Then STDOUT should not be empty
+
+    When I run `wp post update {POST_ID} --post_type=page`
+    Then STDOUT should not be empty
+
+    When I try `wp term migrate grape --by=slug --from=category --to=post_tag`
+    Then STDERR should contain:
+      """
+      Warning: Term 'grape' not assigned to post {POST_ID}. Post type 'page' is not registered with taxonomy 'post_tag'.
+      """
+    And STDOUT should contain:
+      """
+      Success: Migrated the term 'grape' from taxonomy 'category' to taxonomy 'post_tag' for 0 posts.
+      """

src/Term_Command.php

@@ -833,6 +833,12 @@ public function migrate( $args, $assoc_args ) {
 			WP_CLI::error( "Taxonomy '{$original_taxonomy}' doesn't exist." );
 		}
 
+		$dest_tax = get_taxonomy( $destination_taxonomy );
+
+		if ( ! $dest_tax ) {
+			WP_CLI::error( "Taxonomy '{$destination_taxonomy}' doesn't exist." );
+		}
+
 		$id = wp_insert_term(
 			$term->name,
 			$destination_taxonomy,
@@ -850,18 +856,22 @@ public function migrate( $args, $assoc_args ) {
 		/**
 		 * @var string[] $post_ids
 		 */
-		$post_ids = get_objects_in_term( $term->term_id, $tax->name );
+		$post_ids   = get_objects_in_term( $term->term_id, $tax->name );
+		$post_count = 0;
 
 		foreach ( $post_ids as $post_id ) {
 			$type = get_post_type( (int) $post_id );
-			if ( in_array( $type, $tax->object_type, true ) ) {
+			if ( in_array( $type, $dest_tax->object_type, true ) ) {
 				$term_taxonomy_id = wp_set_object_terms( (int) $post_id, $id['term_id'], $destination_taxonomy, true );
 
 				if ( is_wp_error( $term_taxonomy_id ) ) {
 					WP_CLI::error( "Failed to assign the term '{$term->slug}' to the post {$post_id}. Reason: " . $term_taxonomy_id->get_error_message() );
 				}
 
 				WP_CLI::log( "Term '{$term->slug}' assigned to post {$post_id}." );
+				++$post_count;
+			} else {
+				WP_CLI::warning( "Term '{$term->slug}' not assigned to post {$post_id}. Post type '{$type}' is not registered with taxonomy '{$destination_taxonomy}'." );
 			}
 
 			clean_post_cache( (int) $post_id );
@@ -878,7 +888,6 @@ public function migrate( $args, $assoc_args ) {
 		}
 
 		WP_CLI::log( "Old instance of term '{$term->slug}' removed from its original taxonomy." );
-		$post_count  = count( $post_ids );
 		$post_plural = Utils\pluralize( 'post', $post_count );
 		WP_CLI::success( "Migrated the term '{$term->slug}' from taxonomy '{$tax->name}' to taxonomy '{$destination_taxonomy}' for {$post_count} {$post_plural}." );
 	}