fix: support httpmock generation for array types

Author: daniel.eades

progenitor-impl/tests/test_httpmock_query_arrays.rs

@@ -0,0 +1,57 @@
+// Copyright 2025 Oxide Computer Company
+
+use openapiv3::OpenAPI;
+use progenitor_impl::{space_out_items, Generator};
+
+fn format_httpmock(generator: &mut Generator, spec: &OpenAPI) -> String {
+    let code = generator.httpmock(spec, "crate::types").unwrap();
+    let output = rustfmt_wrapper::rustfmt_config(
+        rustfmt_wrapper::config::Config {
+            format_strings: Some(true),
+            ..Default::default()
+        },
+        code,
+    )
+    .unwrap();
+    space_out_items(output).unwrap()
+}
+
+#[test]
+fn test_httpmock_query_array_param() {
+    let spec = serde_yaml::from_str::<OpenAPI>(
+        r#"
+openapi: 3.0.0
+info:
+  title: httpmock-query-array
+  version: "0.0.0"
+paths:
+  /widgets:
+    get:
+      operationId: listWidgets
+      parameters:
+        - name: tags
+          in: query
+          required: true
+          schema:
+            type: array
+            items:
+              type: string
+      responses:
+        "204":
+          description: no-content
+"#,
+    )
+    .unwrap();
+
+    let mut generator = Generator::default();
+    let output = format_httpmock(&mut generator, &spec);
+
+    assert!(
+        output.contains("matches_query_param(req, \"tags\", &value)"),
+        "expected array query params to use serialized query matching"
+    );
+    assert!(
+        !output.contains("query_param(\"tags\", value.to_string())"),
+        "expected array query params to avoid Display-based matching"
+    );
+}