build(nodejs): make default_version optional (#1368)

Benjamin E. Coe · web-flow · commit 1f06210ad31b · 2022-03-16T11:25:29.000-04:00
diff --git a/synthtool/gcp/templates/node_split_library/index.ts.j2 b/synthtool/gcp/templates/node_split_library/index.ts.j2
@@ -17,9 +17,9 @@
 // ** All changes to this file may be overwritten. **
 
 {% for version in versions %}import * as {{ version }} from './{{ version}}';{{ "\n" }}{% endfor %}
-{% for client in clients %}const {{ client }} = {{ default_version }}.{{ client }};
-type {{ client }} = {{ default_version }}.{{ client }};{{ "\n" }}{% endfor %}
-export {{ "{" }}{{ versions|join(', ')}}, {{ clients|join(', ')}}{{ "}" }};
-export default {{ "{" }}{{ versions|join(', ')}}, {{ clients|join(', ')}}{{ "}" }};
+{% if default_version is defined %}{% for client in clients %}const {{ client }} = {{ default_version }}.{{ client }};
+type {{ client }} = {{ default_version }}.{{ client }};{{ "\n" }}{% endfor %}{% endif %}
+export {{ "{" }}{{ versions|join(', ')}}{% if clients|length > 0 %}, {{ clients|join(', ')}}{% endif %}{{ "}" }};
+export default {{ "{" }}{{ versions|join(', ')}}{% if clients|length > 0 %}, {{ clients|join(', ')}}{% endif %}{{ "}" }};
 import * as protos from '../protos/protos';
 export {protos};
diff --git a/synthtool/languages/node.py b/synthtool/languages/node.py
@@ -132,21 +132,23 @@ def generate_index_ts(versions: List[str], default_version: str) -> None:
         )
         logger.error(err_msg)
         raise AttributeError(err_msg)
-    if default_version not in versions:
+    if default_version and default_version not in versions:
         err_msg = f"Version {versions} must contain default version {default_version}."
         logger.error(err_msg)
         raise AttributeError(err_msg)
 
     # To make sure the output is always deterministic.
     versions = sorted(versions)
 
-    # compose default version's index.ts file path
-    versioned_index_ts_path = Path("src") / default_version / "index.ts"
-    clients = extract_clients(versioned_index_ts_path)
-    if not clients:
-        err_msg = f"No client is exported in the default version's({default_version}) index.ts ."
-        logger.error(err_msg)
-        raise AttributeError(err_msg)
+    # compose default version's index.ts file
+    clients = []
+    if default_version:
+        versioned_index_ts_path = Path("src") / default_version / "index.ts"
+        clients = extract_clients(versioned_index_ts_path)
+        if not clients:
+            err_msg = f"No client is exported in the default version's({default_version}) index.ts ."
+            logger.error(err_msg)
+            raise AttributeError(err_msg)
 
     # compose template directory
     template_path = (
@@ -297,14 +299,14 @@ def owlbot_main(
     )
     staging = Path("owl-bot-staging")
     s_copy = transforms.move
-    if default_version is None:
-        logger.info("No default version found in .repo-metadata.json.  Ok.")
-    elif staging.is_dir():
+    versions = []
+    if staging.is_dir():
         logger.info(f"Copying files from staging directory ${staging}.")
         # Collect the subdirectories of the staging directory.
         versions = [v.name for v in staging.iterdir() if v.is_dir()]
         # Reorder the versions so the default version always comes last.
-        versions = [v for v in versions if v != default_version] + [default_version]
+        if default_version:
+            versions = [v for v in versions if v != default_version] + [default_version]
         logger.info(f"Collected versions ${versions} from ${staging}")
 
         # Copy each version directory into the root.
@@ -320,12 +322,13 @@ def owlbot_main(
         src = Path("src")
         versions = [v.name for v in src.iterdir() if v.is_dir()]
         # Reorder the versions so the default version always comes last.
-        versions = [v for v in versions if v != default_version] + [default_version]
+        if default_version:
+            versions = [v for v in versions if v != default_version] + [default_version]
         logger.info(f"Collected versions ${versions} from ${src}")
 
     common_templates = gcp.CommonTemplates(template_path)
     common_templates.excludes.extend(templates_excludes)
-    if default_version:
+    if len(versions) > 0:
         templates = common_templates.node_library(
             source_location="build/src",
             versions=versions,
diff --git a/tests/test_node.py b/tests/test_node.py
@@ -102,6 +102,16 @@ def test_extract_multiple_clients():
     assert clients[1] == "VideoIntelligenceServiceClient"
 
 
+def test_generate_index_ts_no_default_version():
+    # use a non-nodejs template directory
+    with util.chdir(FIXTURES / "node_templates" / "index_samples"):
+        versions = ["v1beta1"]
+        node.generate_index_ts(versions, None)
+        text = open("./src/index.ts", "rt").read()
+        assert "export {v1beta1};" in text
+        assert "export default {v1beta1};" in text
+
+
 def test_generate_index_ts():
     # use a non-nodejs template directory
     with util.chdir(FIXTURES / "node_templates" / "index_samples"):
