Render post-install pages for Windows when input is a string

constructor/winexe.py

@@ -365,9 +365,12 @@ def make_nsi(
         if variables['custom_conclusion']
         else ''
     )
-    variables['POST_INSTALL_PAGES'] = '\n'.join(
-        custom_nsi_insert_from_file(file) for file in info.get('post_install_pages', [])
-    )
+    if isinstance(info.get("post_install_pages"), str):
+        variables["POST_INSTALL_PAGES"] = custom_nsi_insert_from_file(info["post_install_pages"])
+    else:
+        variables['POST_INSTALL_PAGES'] = '\n'.join(
+            custom_nsi_insert_from_file(file) for file in info.get('post_install_pages', [])
+        )
     variables['TEMP_EXTRA_FILES'] = '\n    '.join(insert_tempfiles_commands(temp_extra_files))
     variables['VIRTUAL_SPECS'] = " ".join([f'"{spec}"' for spec in info.get("virtual_specs", ())])
     # This is the same but without quotes so we can print it fine

examples/exe_extra_pages/construct.yaml

@@ -1,10 +1,19 @@
-name: extraPages
+{% if os.environ.get("POST_INSTALL_PAGES_LIST") %}
+{% set name = "extraPages" %}
+{% else %}
+{% set name = "extraPageSingle" %}
+{% endif %}
+name: {{ name }}
 version: X
 installer_type: all
 channels:
   - http://repo.anaconda.com/pkgs/main/
 specs:
   - python
+{% if os.environ.get("POST_INSTALL_PAGES_LIST") %}
 post_install_pages:
   - extra_page_1.nsi
   - extra_page_2.nsi
+{% else %}
+post_install_pages: extra_page_1.nsi
+{% endif %}

news/904-post-install-pages-win-fix

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* Correctly parse post-install pages for Windows when input is a string. (#904)
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>

tests/test_examples.py

@@ -378,8 +378,11 @@ def test_example_customized_welcome_conclusion(tmp_path, request):
         _run_installer(input_path, installer, install_dir, request=request)
 
 
+@pytest.mark.parametrize("extra_pages", ("str", "list"))
 @pytest.mark.skipif(sys.platform != "win32", reason="Windows only")
-def test_example_extra_pages_win(tmp_path, request):
+def test_example_extra_pages_win(tmp_path, request, extra_pages, monkeypatch):
+    if extra_pages == "list":
+        monkeypatch.setenv("POST_INSTALL_PAGES_LIST", "1")
     input_path = _example_path("exe_extra_pages")
     for installer, install_dir in create_installer(input_path, tmp_path):
         _run_installer(input_path, installer, install_dir, request=request)