Fix ArgumentError on invalid UTF-8 in tooling job output (#8474)

* Fix ArgumentError on invalid UTF-8 byte sequences in tooling job output

Use .scrub before .blank? to sanitize strings from external tooling
services that may contain invalid UTF-8 byte sequences. This prevents
BLANK_RE regex from raising ArgumentError when matching against them.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Use safe navigation operator for .scrub to handle nil values

When the JSON key doesn't exist in execution_output, the value is nil.
Calling .scrub on nil raises NoMethodError. Using &.scrub allows nil
to fall through to .blank? which correctly returns true for nil.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: iHiD

app/commands/submission/analysis/process.rb

@@ -69,7 +69,7 @@ def tags_data
     return {} if ops_errored?
 
     tags_json = tooling_job.execution_output['tags.json']
-    return {} if tags_json.blank?
+    return {} if tags_json&.scrub.blank?
 
     res = JSON.parse(tags_json)
     res.is_a?(Hash) ? res.symbolize_keys : {}

app/commands/submission/representation/process.rb

@@ -56,7 +56,7 @@ def metadata
     return {} if ops_errored?
 
     representation_json = tooling_job.execution_output['representation.json']
-    return {} if representation_json.blank?
+    return {} if representation_json&.scrub.blank?
 
     res = JSON.parse(representation_json)
     res.is_a?(Hash) ? res.symbolize_keys : {}

app/commands/submission/test_run/process.rb

@@ -115,7 +115,7 @@ def results
     return {} if tooling_job.execution_output.nil?
 
     results_json = tooling_job.execution_output['results.json']
-    return {} if results_json.blank?
+    return {} if results_json&.scrub.blank?
 
     res = JSON.parse(results_json, allow_invalid_unicode: true)
     res.is_a?(Hash) ? res.symbolize_keys : {}

test/commands/submission/test_run/process_test.rb

@@ -67,6 +67,23 @@ class Submission::TestRun::ProcessTest < ActiveSupport::TestCase
     assert submission.reload.tests_exceptioned?
   end
 
+  test "handle invalid UTF-8 in results.json without raising" do
+    submission = create :submission
+    job = create_test_runner_job!(
+      submission,
+      execution_status: 200,
+      results: { 'status' => 'pass', 'tests' => [] }
+    )
+
+    invalid_bytes = "\xFF\xFE".dup.force_encoding('UTF-8')
+    job.stubs(:execution_output).returns({ 'results.json' => invalid_bytes })
+
+    # This should not raise ArgumentError: invalid byte sequence in UTF-8
+    Submission::TestRun::Process.(job)
+
+    assert submission.reload.tests_exceptioned?
+  end
+
   test "handle tests pass" do
     submission = create :submission
     results = { 'status' => 'pass', 'message' => "", 'tests' => [] }