fix: ensure proper formatting of changes_diagram in PR description output

pr_agent/settings/pr_description_prompts.toml

@@ -46,12 +46,12 @@ class PRDescription(BaseModel):
     type: List[PRType] = Field(description="one or more types that describe the PR content. Return the label member value (e.g. 'Bug fix', not 'bug_fix')")
     description: str = Field(description="summarize the PR changes in up to four bullet points, each up to 8 words. For large PRs, add sub-bullets if needed. Order bullets by importance, with each bullet highlighting a key change group.")
     title: str = Field(description="a concise and descriptive title that captures the PR's main theme")
-{%- if enable_semantic_files_types %}
-    pr_files: List[FileDescription] = Field(max_items=20, description="a list of all the files that were changed in the PR, and summary of their changes. Each file must be analyzed regardless of change size.")
-{%- endif %}
 {%- if enable_pr_diagram %}
     changes_diagram: str = Field(description="a horizontal diagram that represents the main PR changes, in the format of a mermaid flowchart. The diagram should be concise and easy to read. Leave empty if no diagram is relevant.")
 {%- endif %}
+{%- if enable_semantic_files_types %}
+    pr_files: List[FileDescription] = Field(max_items=20, description="a list of all the files that were changed in the PR, and summary of their changes. Each file must be analyzed regardless of change size.")
+{%- endif %}
 =====
 
 
@@ -65,6 +65,12 @@ description: |
   ...
 title: |
   ...
+{%- if enable_pr_diagram %}
+  changes_diagram: |
+    ```mermaid
+    ...
+    ```
+{%- endif %}
 {%- if enable_semantic_files_types %}
 pr_files:
 - filename: |
@@ -79,12 +85,6 @@ pr_files:
     label_key_1
 ...
 {%- endif %}
-{%- if enable_pr_diagram %}
-  changes_diagram: |
-    ```mermaid
-    ...
-    ```
-{%- endif %}
 ```
 
 Answer should be a valid YAML, and nothing else. Each YAML output MUST be after a newline, with proper indent, and block scalar indicator ('|')
@@ -152,6 +152,12 @@ description: |
   ...
 title: |
   ...
+{%- if enable_pr_diagram %}
+  changes_diagram: |
+    ```mermaid
+    ...
+    ```
+{%- endif %}
 {%- if enable_semantic_files_types %}
 pr_files:
 - filename: |
@@ -166,12 +172,6 @@ pr_files:
     label_key_1
 ...
 {%- endif %}
-{%- if enable_pr_diagram %}
-  changes_diagram: |
-    ```mermaid
-    ...
-    ```
-{%- endif %}
 ```
 (replace '...' with the actual values)
 {%- endif %}

pr_agent/tools/pr_description.py

@@ -458,9 +458,11 @@ class PRDescription:
         if 'description' in self.data:
             self.data['description'] = self.data.pop('description')
         if 'changes_diagram' in self.data:
-            changes_diagram = self.data.pop('changes_diagram')
-            if changes_diagram.strip():
-                self.data['changes_diagram'] = changes_diagram
+            changes_diagram = self.data.pop('changes_diagram').strip()
+            if changes_diagram.startswith('```'):
+                if not changes_diagram.endswith('```'):  # fallback for missing closing
+                    changes_diagram += '\n```'
+                self.data['changes_diagram'] = '\n'+ changes_diagram
         if 'pr_files' in self.data:
             self.data['pr_files'] = self.data.pop('pr_files')