Fix trailing wrapper text removal in Layer 1 content cleaning (fixes #1)

This commit addresses GitHub issue #1 where JSON followed by wrapper text
was not being properly cleaned by the content cleaning layer.

Changes:
- Added remove_trailing_wrapper_text/1 function to detect and remove text
  following valid JSON structures
- Updated extract_json_content_internal/2 to call the new function as a
  final extraction step
- Added test case specifically for the reported issue with JSON arrays
  followed by status messages

The fix ensures that when JSON content is extracted, any trailing
non-JSON text (like "1 Volume(s) created") is properly removed,
returning only the valid JSON structure.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: 2 people

lib/json_remedy/layer1/content_cleaning.ex

@@ -87,7 +87,10 @@ defmodule JsonRemedy.Layer1.ContentCleaning do
     # Then try to extract from prose/text
     {result, prose_repairs} = extract_from_prose(result)
 
-    all_repairs = existing_repairs ++ html_repairs ++ prose_repairs
+    # Finally, remove any trailing wrapper text after JSON
+    {result, trailing_repairs} = remove_trailing_wrapper_text(result)
+
+    all_repairs = existing_repairs ++ html_repairs ++ prose_repairs ++ trailing_repairs
     {result, all_repairs}
   end
 
@@ -682,6 +685,66 @@ defmodule JsonRemedy.Layer1.ContentCleaning do
     find_balanced_end(rest, open, close, pos + 1, balance, in_string)
   end
 
+  # Remove trailing wrapper text after JSON
+  defp remove_trailing_wrapper_text(input) do
+    trimmed = String.trim(input)
+
+    # Check if input starts with JSON structure
+    cond do
+      String.starts_with?(trimmed, "{") ->
+        check_and_remove_trailing_text(input, "{", "}")
+
+      String.starts_with?(trimmed, "[") ->
+        check_and_remove_trailing_text(input, "[", "]")
+
+      true ->
+        {input, []}
+    end
+  end
+
+  defp check_and_remove_trailing_text(input, open_char, close_char) do
+    # Find where the JSON structure starts
+    json_start =
+      case String.split(input, open_char, parts: 2) do
+        [prefix, _] -> String.length(prefix)
+        _ -> 0
+      end
+
+    # Extract from the JSON start to find the balanced end
+    substring_from_json = String.slice(input, json_start, String.length(input))
+
+    case find_balanced_end(substring_from_json, open_char, close_char) do
+      nil ->
+        # Could not find balanced end, return as is
+        {input, []}
+
+      end_pos ->
+        # Calculate the absolute position where JSON ends
+        json_end = json_start + end_pos + 1
+
+        # Check if there's non-whitespace content after JSON ends
+        after_json = String.slice(input, json_end, String.length(input))
+
+        if String.trim(after_json) == "" do
+          # No significant trailing content
+          {input, []}
+        else
+          # Extract only the JSON portion
+          json_content = String.slice(input, 0, json_end)
+
+          repair = %{
+            layer: :content_cleaning,
+            action: "removed trailing wrapper text",
+            position: json_end,
+            original: input,
+            replacement: json_content
+          }
+
+          {json_content, [repair]}
+        end
+    end
+  end
+
   # Helper functions for string detection using direct methods
 
   # Fast check for long text that likely contains JSON content

test/unit/layer1_content_cleaning_test.exs

@@ -174,6 +174,36 @@ defmodule JsonRemedy.Layer1.ContentCleaningTest do
         assert length(context.repairs) > 0
       end
     end
+
+    test "extracts json with trailing wrapper text (GitHub issue #1)" do
+      # This test case reproduces the issue where JSON followed by text is not cleaned
+      input = """
+      [
+        {
+          "volumeID": "f3a6ffd2-0111-4235-980c-a5ceec215e93",
+          "name": "km-tst-20",
+          "cloudID": "75b10103873d4a1ba0d52b43159a2842",
+          "size": 1,
+          "storageType": "ssd",
+          "state": "creating",
+          "shareable": false,
+          "bootable": false,
+          "volumePool": "General-Flash-002"
+        }
+      ]
+      1 Volume(s) created
+      """
+
+      {:ok, result, context} = ContentCleaning.process(input, %{repairs: [], options: []})
+
+      # Should extract only the JSON array, removing the trailing text
+      trimmed_result = String.trim(result)
+      assert String.starts_with?(trimmed_result, "[")
+      assert String.ends_with?(trimmed_result, "]")
+      assert not String.contains?(result, "1 Volume(s) created")
+      assert length(context.repairs) > 0
+      assert hd(context.repairs).action =~ "removed trailing wrapper text"
+    end
   end
 
   describe "encoding normalization" do