From f14c09406ad5bfc5c59e0a6c1e1a33aa132d3eae Mon Sep 17 00:00:00 2001
From: Juan Leyva <juanleyvadelgado@gmail.com>
Date: Thu, 20 Apr 2023 11:13:23 +0200
Subject: [PATCH 1/2] MDL-77229 lesson: Fix error for empty responses
 (numerical pagetype)

---
 mod/lesson/pagetypes/numerical.php | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/mod/lesson/pagetypes/numerical.php b/mod/lesson/pagetypes/numerical.php
index a697cc5a9c56c..c5c79553279e5 100644
--- a/mod/lesson/pagetypes/numerical.php
+++ b/mod/lesson/pagetypes/numerical.php
@@ -255,9 +255,12 @@ public function report_answers($answerpage, $answerdata, $useranswer, $pagestats
                     $total = $stats["total"];
                     unset($stats["total"]);
                     foreach ($stats as $valentered => $ntimes) {
+                        $valformatted = '';
+                        if (!is_null($valentered) && trim($valentered) !== '') {  // Empty response, 0 could be ok.
+                            $valformatted = s(format_float($valentered, strlen($valentered), true, true));
+                        }
                         $data = '<input class="form-control" type="text" size="50" ' .
-                                'disabled="disabled" readonly="readonly" value="'.
-                                s(format_float($valentered, strlen($valentered), true, true)).'" />';
+                                'disabled="disabled" readonly="readonly" value="'. $valformatted .'" />';
                         $percent = $ntimes / $total * 100;
                         $percent = round($percent, 2);
                         $percent .= "% ".get_string("enteredthis", "lesson");
@@ -270,9 +273,12 @@ public function report_answers($answerpage, $answerdata, $useranswer, $pagestats
             } else if ($useranswer != null && ($answer->id == $useranswer->answerid || ($answer == end($answers) &&
                     empty($answerdata->answers)))) {
                 // Get in here when the user answered or for the last answer.
+                $valformatted = '';
+                if (!is_null($useranswer->useranswer) && trim($useranswer->useranswer) !== '') {  // Empty response, 0 could be ok.
+                    $valformatted = s(format_float($useranswer->useranswer, strlen($useranswer->useranswer), true, true));
+                }
                 $data = '<input class="form-control" type="text" size="50" ' .
-                        'disabled="disabled" readonly="readonly" value="'.
-                        s(format_float($useranswer->useranswer, strlen($useranswer->useranswer), true, true)).'">';
+                        'disabled="disabled" readonly="readonly" value="' . $valformatted .'">';
                 if (isset($pagestats[$this->properties->id][$useranswer->useranswer])) {
                     $percent = $pagestats[$this->properties->id][$useranswer->useranswer] / $pagestats[$this->properties->id]["total"] * 100;
                     $percent = round($percent, 2);

From 1601a2610fa461e3ff742f742edf6a725541d5b1 Mon Sep 17 00:00:00 2001
From: Ilya Tregubov <ilya@moodle.com>
Date: Fri, 21 Apr 2023 11:59:27 +0800
Subject: [PATCH 2/2] MDL-77229 lesson: Add Behat test

---
 mod/lesson/tests/behat/lesson_report.feature | 23 ++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/mod/lesson/tests/behat/lesson_report.feature b/mod/lesson/tests/behat/lesson_report.feature
index ee2b9074bc9d2..869ccb89dcb97 100644
--- a/mod/lesson/tests/behat/lesson_report.feature
+++ b/mod/lesson/tests/behat/lesson_report.feature
@@ -9,6 +9,7 @@ Feature: In a lesson activity, teachers can review student attempts
       | username | firstname | lastname | email |
       | teacher1 | Teacher | 1 | teacher1@example.com |
       | student1 | Student | 1 | student1@example.com |
+      | student2 | Student | 2 | student2@example.com |
     And the following "courses" exist:
       | fullname | shortname | category |
       | Course 1 | C1 | 0 |
@@ -16,6 +17,7 @@ Feature: In a lesson activity, teachers can review student attempts
       | user | course | role |
       | teacher1 | C1 | editingteacher |
       | student1 | C1 | student |
+      | student2 | C1 | student |
     And the following "activities" exist:
       | activity   | name             | course | idnumber    | retake |
       | lesson     | Test lesson name | C1     | lesson1     | 1      |
@@ -149,3 +151,24 @@ Feature: In a lesson activity, teachers can review student attempts
     And I should not see "High score"
     And I should not see "Average score"
     And I should not see "Low score"
+
+  Scenario: View detailed statistics in a lesson when empty string is given as answer
+    Given I follow "Add a question page"
+    And I set the field "Select a question type" to "Numerical"
+    And I press "Add a question page"
+    And I set the following fields to these values:
+      | Page title | Numerical question |
+      | Page contents | What is 1 + 0.5? |
+      | id_answer_editor_0 | 1.5 |
+      | id_jumpto_0 | End of lesson |
+    And I press "Save page"
+    When I am on the "Test lesson name" "lesson activity" page logged in as student1
+    And I press "Submit"
+    And I log out
+    And I am on the "Test lesson name" "lesson activity" page logged in as student2
+    And I set the field "Your answer" to "1.5"
+    And I press "Submit"
+    And I am on the "Test lesson name" "lesson activity" page logged in as teacher1
+    And I navigate to "Reports" in current page administration
+    And I select "Detailed statistics" from the "jump" singleselect
+    Then I should see "50% entered this."