Fix multiple interpolation

CHANGELOG.rst

@@ -7,6 +7,7 @@ v0.8 (unreleased)
 ====
 
 Test with Python 3.9 and Python 3.10.
+Fix interpolation of multiple variables in one setting value.
 
 
 v0.7

configstore/store.py

@@ -73,7 +73,7 @@ def get_setting(self, key, default=_no_default, *, asbool=False):
         return ret
 
     def interpolate(self, string):
-        res = re.sub(r"\$\{([_a-zA-Z0-9]+)\}", self._replace, string, count=1)
+        res = re.sub(r"\$\{([_a-zA-Z0-9]+)\}", self._replace, string)
         return res
 
     def _replace(self, matchobj):

tests/test_store.py

@@ -74,6 +74,13 @@ def test_store_get_setting_interpolate_value():
     assert value == '42-staging-secrets!'
 
 
+def test_store_get_setting_interpolate_missing():
+    store = Store([DictBackend({'service_host': 'cool-db-server:6000'})])
+
+    with pytest.raises(SettingNotFoundException):
+        store.get_setting('service_url')
+
+
 def test_store_get_setting_interpolate_default():
     store = Store([DictBackend({'service_host': 'cool-db-server:6000'})])
 
@@ -82,6 +89,21 @@ def test_store_get_setting_interpolate_default():
     assert value == 'https://cool-db-server:6000/db'
 
 
+def test_store_get_setting_interpolate_special_character_boundary():
+    store = Store([DictBackend(dict(
+        service_url='https://${user}:${dbpass}@${host}:${port}/${db}',
+        user='bob',
+        dbpass='secret',
+        host='cool-db-server',
+        port='6000',
+        db='db1',
+    ))])
+
+    value = store.get_setting('service_url')
+
+    assert value == 'https://bob:secret@cool-db-server:6000/db1'
+
+
 def test_store_add_backend():
     store = Store([])
 

tests/test_z_integration.py

@@ -89,10 +89,15 @@ def test_dict_defaults(monkeypatch):
 
 def test_interpolation(monkeypatch, tmp_path):
     monkeypatch.setenv('ENVIRONMENT', 'STAGING')
-    monkeypatch.setenv('REDIS_URL', 'https://redis:4012')
+    monkeypatch.setenv('REDIS_HOST', 'redis')
+    monkeypatch.setenv('REDIS_PORT', '4012')
     path = tmp_path / 'config.env'
     path.write_text(DOTENV_CONTENTS)
-    path.write_text('APP_NAME=supertest-${ENVIRONMENT}-1')
+    path.write_text(
+        'APP_NAME=supertest-${ENVIRONMENT}-1\n'
+        # make sure more than one variable is possible
+        'REDIS_URL=https://${REDIS_HOST}:${REDIS_PORT}\n'
+    )
 
     store = configstore.Store([
         configstore.EnvVarBackend(),