Bug 1929903 - Preserve object property names in Rust JSON

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Rust and Rust Sym: Preserve object metric property names containing dots, hyphens, or uppercase letters when serializing and deserializing JSON ([bug 1929903](https://bugzilla.mozilla.org/show_bug.cgi?id=1929903)).
 - Support `flows.yaml` files (`moz://mozilla.org/schemas/glean/flows/1-0-0`), declaring multi-step tasks measured as a unit over existing event metrics. Flows are validated against the metrics passed to the parser, with warnings for events that aren't defined in any of them (`UNRESOLVED_FLOW_EVENT`) and for flows with no exit events (`EMPTY_ENDS_ON`). Kotlin, Swift, and Rust output gains the flow definitions to pass to Glean at initialization (`GleanFlows`), and Markdown output documents flows and the flows each event belongs to. Flows are passed to external translators as the `flows` option ([bug 2077133](https://bugzilla.mozilla.org/show_bug.cgi?id=2077133))
 - Fix tests that failed when `SOURCE_DATE_EPOCH` is set in the environment
 - Add a `skip_schema_validation` option to `parse_objects` to skip schema validation of input files ([bug 2076540](https://bugzilla.mozilla.org/show_bug.cgi?id=2076540))

glean_parser/templates/rust.jinja2

@@ -29,6 +29,7 @@ Jinja2 template is not. Please file bugs! #}
     #[serde(deny_unknown_fields)]
     pub struct {{ name }} {
         {% for itemname, val in struct.properties.items() %}
+          #[serde(rename = "{{ itemname }}")]
           {% if val.type == "array" %}
           #[serde(skip_serializing_if = "Vec::is_empty", default = "Vec::new", deserialize_with = "::glean::traits::__serde_helper::vec_null")]
           pub {{itemname|snake_case}}: {{ name ~ itemname|Camelize }},

glean_parser/templates/rust_sym.jinja2

@@ -29,6 +29,7 @@ Jinja2 template is not. Please file bugs! #}
     #[serde(deny_unknown_fields)]
     pub struct {{ name }} {
         {% for itemname, val in struct.properties.items() %}
+          #[serde(rename = "{{ itemname }}")]
           {% if val.type == "array" %}
           #[serde(skip_serializing_if = "Vec::is_empty", default = "Vec::new", deserialize_with = "::glean_sym::__serde_helper::vec_null")]
           pub {{itemname|snake_case}}: {{ name ~ itemname|Camelize }},

tests/data/object.yaml

@@ -52,11 +52,11 @@ complex.types:
     structure:
       type: object
       properties:
-        key1:
+        foo.bar-baz:
           type: string
-        another_value:
+        CamelCase:
           type: number
-        sub_array:
+        sub-array:
           type: array
           items:
             type: number
@@ -79,7 +79,7 @@ complex.types:
         properties:
           key:
             type: string
-          value:
+          choice-value:
             oneOf:
               - type: string
               - type: number
@@ -91,7 +91,7 @@ activity.stream:
     type: object
     description: |
       The id, position, and shim for each newtab tile and any extra nested data,
-      e.g. `[{"id": 1, "pos": 2, "shim": "long-id", "nested": { "count": 17, "info": "more info"}}]`
+      e.g. `[{"id": 1, "pos": 2, "shim": "long-id", "nested-object": { "count": 17, "nested.info": "more info"}}]`
     bugs:
       - https://bugzilla.mozilla.org/11137353
     data_reviews:
@@ -110,12 +110,12 @@ activity.stream:
             type: number
           shim:
             type: string
-          nested:
+          nested-object:
             type: object
             properties:
               count:
                 type: number
-              info:
+              nested.info:
                 type: string
 
 crash.stack:

tests/test_rust.py

@@ -8,6 +8,8 @@
 import subprocess
 import re
 
+import pytest
+
 from glean_parser import rust
 from glean_parser import metrics
 from glean_parser import pings
@@ -257,13 +259,12 @@ def test_event_extra_keys_with_types(tmp_path):
         )
 
 
-def test_object_metric(tmp_path):
-    """
-    Assert that an object metric is created.
-    """
+@pytest.mark.parametrize("output_format", ["rust", "rust_sym"])
+def test_object_metric(tmp_path, output_format):
+    """Assert that object metrics preserve their property names in JSON."""
     translate.translate(
         ROOT / "data" / "object.yaml",
-        "rust",
+        output_format,
         tmp_path,
         {"namespace": "Foo"},
     )
@@ -288,6 +289,21 @@ def test_object_metric(tmp_path):
         assert "trust: Option<String>, " in content
         assert "}" in content
 
+        for original, field in [
+            ("foo.bar-baz", "foo_bar_baz"),
+            ("CamelCase", "camelcase"),
+            ("sub-array", "sub_array"),
+            ("nested-object", "nested_object"),
+            ("nested.info", "nested_info"),
+            ("choice-value", "choice_value"),
+            ("module_index", "module_index"),
+        ]:
+            assert re.search(
+                rf'#\[serde\(rename = "{re.escape(original)}"\)\] '
+                + rf"#\[serde\([^\]]*\)\] pub {field}:",
+                content,
+            )
+
 
 def test_in_session_output(tmp_path):
     """Assert that in_session: true produces in_session: true in Rust output."""