fix(render): Reverse Mermaid feature detection so it gets picked up

We were previously assigning the global variable to the local record, rather than accumulating the local record into the global variable.

This change also adds tests to capture this failure in future.

adr_viewer/__init__.py

@@ -3,7 +3,12 @@
 from click import option, command
 
 from adr_viewer.parse import parse_adr, parse_adr_files, Adr
-from adr_viewer.render import render_html, AdrTemplateConfig, generate_content
+from adr_viewer.render import (
+    generate_configuration,
+    render_html,
+    AdrTemplateConfig,
+    generate_content,
+)
 from adr_viewer.server import run_server
 
 

adr_viewer/render.py

@@ -33,15 +33,19 @@ def render_html(config: AdrTemplateConfig, template_dir_override=None) -> str:
     return template.render(config=config)
 
 
-def generate_content(adrs: List[Adr], template_dir_override=None, title=None) -> str:
+def generate_configuration(adrs: List[Adr], title=None):
     config = AdrTemplateConfig(
         project_title=title if title else os.path.basename(os.getcwd()), records=[]
     )
 
     for index, adr in enumerate(adrs):
         adr.index = index
-        adr.includes_mermaid |= config.include_mermaid
+        config.include_mermaid |= adr.includes_mermaid
 
         config.records.append(adr)
 
-    return render_html(config, template_dir_override)
+    return config
+
+
+def generate_content(adrs: List[Adr], template_dir_override=None, title=None) -> str:
+    return render_html(generate_configuration(adrs, title), template_dir_override)

adr_viewer/test_render.py

@@ -1,4 +1,4 @@
-from adr_viewer import render_html, AdrTemplateConfig
+from adr_viewer import generate_configuration, render_html, AdrTemplateConfig
 from adr_viewer.parse import Adr
 
 
@@ -46,3 +46,20 @@ def test_should_render_html_without_mermaid():
     )
 
     assert "mermaid.min.js" not in html
+
+
+def test_should_add_mermaid_dependency_to_overall_render():
+    adr = Adr("Record 123", "status", "content")
+    adr.includes_mermaid = True
+
+    config = generate_configuration(adrs=[adr], title="title")
+
+    assert config.include_mermaid
+
+
+def test_should_not_add_mermaid_dependency_to_overall_render_if_not_needed():
+    adr = Adr("Record 123", "status", "content")
+
+    config = generate_configuration(adrs=[adr], title="title")
+
+    assert not config.include_mermaid