MDLSITE-6745 mustachelint: Ensure that fatal errors include a source

mustache_lint/js_helper.php

@@ -81,6 +81,23 @@ public function run_eslint() {
         }
 
         // We should only have problem messages for the one file passed.
-        return $problems[0]->messages;
+        $messages = $problems[0]->messages;
+
+        foreach ($messages as $problem) {
+            $problem->linesource = '';
+            if ($problem->line) {
+                $lines = explode("\n", $this->js, $problem->line);
+                if ($lines && count($lines) === $problem->line) {
+                    $problem->linesource = array_pop($lines);
+                }
+            }
+            if (!property_exists($problem, 'source')) {
+                // Fatal errors do not include a source.
+                // Fill the entire source line.
+                $problem->source = $problem->linesource;
+            }
+        }
+
+        return $messages;
     }
 }

tests/1-mustache_lint.bats

@@ -180,6 +180,24 @@ setup () {
     assert_output --partial "lib/templates/js_test.mustache - WARNING: ESLint warning [no-alert]: Unexpected alert. ( alert(my_message); )"
 }
 
+@test "mustache_lint: Test eslint handles parsing failures safely" {
+
+    # a8c64d6 has eslint in package.json (switch to v3.1.3 when releaseD)
+    create_git_branch MOODLE_31_STABLE a8c64d6267fd0a2f12435ea75af88eb4de980d6f
+    git_apply_fixture 31-mustache_lint-js_token_test.patch
+    export GIT_PREVIOUS_COMMIT=$FIXTURE_HASH_BEFORE
+    export GIT_COMMIT=$FIXTURE_HASH_AFTER
+
+    # Install npm depends so we have eslint
+    ci_run prepare_npm_stuff/prepare_npm_stuff.sh
+    # Run with eslint.
+    ci_run mustache_lint/mustache_lint.sh
+
+    # Assert result
+    assert_failure
+    assert_output --partial "lib/templates/js_token_test.mustache - WARNING: ESLint error []: Parsing error: Unexpected token bar ( var foo bar baz = 'bum'; )"
+}
+
 @test "mustache_lint: Test eslint runs ok when invoked from any directory" {
 
     # We need to use recent version here, the default 3.1.3 used for tests (that already had eslint)

tests/fixtures/31-mustache_lint-js_token_test.patch

@@ -0,0 +1,34 @@
+From 7c4ad58c7f7a462e39577959a6c4e05a868cc610 Mon Sep 17 00:00:00 2001
+From: Andrew Nicols <[email protected]>
+Date: Mon, 8 Aug 2022 15:07:36 +0800
+Subject: [PATCH 1/1] MDL-12345 mustache: fixture for js parsing failure
+ detection
+
+---
+ lib/templates/js_token_test.mustache | 14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+ create mode 100644 lib/templates/js_token_test.mustache
+
+diff --git a/lib/templates/js_token_test.mustache b/lib/templates/js_token_test.mustache
+new file mode 100644
+index 0000000000..022896ea27
+--- /dev/null
++++ b/lib/templates/js_token_test.mustache
+@@ -0,0 +1,14 @@
++{{!
++    @template core/js_token_test
++
++    Fixture for testing eslint parsing errors.
++
++    Example context (json):
++    {
++        "text": "World!"
++    }
++}}
++<p>Hello {{text}}</p>
++{{#js}}
++    var foo bar baz = 'bum';
++{{/js}}
+-- 
+2.37.0
+