gsetup: Rework version string handling

I split the function into two. Calling env_string() will return the
string we generate with the versions of the various modules we depend
on. Calling print_env() will print this string.

I need env_string() so we can set the environment as a tooltip in the
header.

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

emmental/__init__.py

@@ -250,7 +250,7 @@ class Application(Adw.Application):
         """Handle any command line options."""
         if opts.contains("version"):
             print(VERSION_STRING)
-            gsetup.print_versions()
+            gsetup.print_env()
             return 0
         return -1
 

emmental/gsetup.py

@@ -40,26 +40,31 @@ def add_style():
                                    CSS_PROVIDER, CSS_PRIORITY)
 
 
-def __print_version(subsystem, major, minor, micro):
-    print(f"  ⋅ {subsystem} {major}.{minor}.{micro}")
+def __version_string(subsystem, major, minor, micro):
+    return f"  ⋅ {subsystem} {major}.{minor}.{micro}"
 
 
-def print_versions():
-    """Print version information for libraries we use."""
-    __print_version("Python", sys.version_info.major, sys.version_info.minor,
-                    sys.version_info.micro)
-    __print_version("Gtk", gi.repository.Gtk.MAJOR_VERSION,
-                    gi.repository.Gtk.MINOR_VERSION,
-                    gi.repository.Gtk.MICRO_VERSION)
-    __print_version("Libadwaita", gi.repository.Adw.MAJOR_VERSION,
-                    gi.repository.Adw.MINOR_VERSION,
-                    gi.repository.Adw.MICRO_VERSION)
-    __print_version("GStreamer", gi.repository.Gst.version().major,
-                    gi.repository.Gst.version().minor,
-                    gi.repository.Gst.version().micro)
-    __print_version("Pango", gi.repository.Pango.VERSION_MAJOR,
-                    gi.repository.Pango.VERSION_MINOR,
-                    gi.repository.Pango.VERSION_MICRO)
-    __print_version("SQLite", sqlite3.sqlite_version_info[0],
-                    sqlite3.sqlite_version_info[1],
-                    sqlite3.sqlite_version_info[2])
+def env_string() -> str:
+    """Return a string with the version numbers of our dependencies."""
+    gst = gi.repository.Gst.version()
+    strs = [__version_string("Python", sys.version_info.major,
+                             sys.version_info.minor, sys.version_info.micro),
+            __version_string("Gtk", gi.repository.Gtk.MAJOR_VERSION,
+                             gi.repository.Gtk.MINOR_VERSION,
+                             gi.repository.Gtk.MICRO_VERSION),
+            __version_string("Libadwaita", gi.repository.Adw.MAJOR_VERSION,
+                             gi.repository.Adw.MINOR_VERSION,
+                             gi.repository.Adw.MICRO_VERSION),
+            __version_string("GStreamer", gst.major, gst.minor, gst.micro),
+            __version_string("Pango", gi.repository.Pango.VERSION_MAJOR,
+                             gi.repository.Pango.VERSION_MINOR,
+                             gi.repository.Pango.VERSION_MICRO),
+            __version_string("SQLite", sqlite3.sqlite_version_info[0],
+                             sqlite3.sqlite_version_info[1],
+                             sqlite3.sqlite_version_info[2])]
+    return "\n".join(strs)
+
+
+def print_env() -> None:
+    """Print the environment versions to stdout."""
+    print(env_string())

tests/test_gsetup.py

@@ -4,6 +4,7 @@ import unittest
 import pathlib
 import emmental
 import gi
+import io
 import xdg.BaseDirectory
 
 
@@ -65,3 +66,20 @@ class TestGSetup(unittest.TestCase):
         """Check that the DATA_DIR points to the right place."""
         data_path = xdg.BaseDirectory.save_data_path("emmental")
         self.assertEqual(emmental.gsetup.DATA_DIR, pathlib.Path(data_path))
+
+    def test_env_string(self):
+        """Check that the env_string() function works as expected."""
+        self.assertRegex(emmental.gsetup.env_string(),
+                         r"  ⋅ Python \d+\.\d+\.\d+\n"
+                         r"  ⋅ Gtk \d+\.\d+\.\d+\n"
+                         r"  ⋅ Libadwaita \d+\.\d+\.\d+\n"
+                         r"  ⋅ GStreamer \d+\.\d+\.\d+\n"
+                         r"  ⋅ Pango \d+\.\d+\.\d+\n"
+                         r"  ⋅ SQLite \d+\.\d+\.\d+$")
+
+    @unittest.mock.patch("sys.stdout", new_callable=io.StringIO)
+    def test_print_env(self, mock_stdout: io.StringIO):
+        """Check that the print_env() function prints the env_string()."""
+        emmental.gsetup.print_env()
+        self.assertEqual(mock_stdout.getvalue(),
+                         emmental.gsetup.env_string() + "\n")