Filter course IDs associated with a given teacher

changelog/fix-co-teachers-get-students

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Filter course IDs associated with a given teacher

includes/class-sensei-teacher.php

@@ -838,7 +838,19 @@ public function filter_learners_query( $learners_sql ) {
 			return $learners_sql;
 		}
 
-		$teacher_course_ids = $this->get_teacher_courses( get_current_user_id(), true );
+		/**
+		 * Filter the course IDs associated with a given teacher.
+		 *
+		 * @since $$next-version$$
+		 *
+		 * @hook sensei_teacher_course_ids
+		 *
+		 * @param {int[]} $course_ids Course IDs for which the current user is the teacher.
+		 * @param {int}   $teacher_id Teacher ID.
+		 * @return {int[]} Filtered course IDs associated with a given teacher.
+		 */
+		$teacher_course_ids = apply_filters( 'sensei_teacher_course_ids', $this->get_teacher_courses( get_current_user_id(), true ), get_current_user_id() );
+
 		if ( ! $teacher_course_ids ) {
 			$teacher_course_ids = [ 0 ]; // Show no learners.
 		}

tests/unit-tests/test-class-teacher.php

@@ -502,7 +502,7 @@ public function testUpdateCourseLessonsAuthor_WhenLessonsAreInDraftStatus_GetAut
 		$this->assertPostAuthor( $new_teacher_id, $course['lesson_ids'], 'All lessons must be from teacher B now' );
 	}
 
-	public function testFilterLearnersQuery_WhenUserIsNoATeacher_ReturnsSameInput() {
+	public function testFilterLearnersQuery_WhenUserIsNotATeacher_ReturnsSameInput() {
 		// Arrange.
 		set_current_screen( 'sensei-lms_page_sensei_learners' ); // Pretend we're on the students admin screen.