[core-client-rest] Fix serialization of non-string path parameters (#…

…31352)

### Packages impacted by this PR

- `@azure-rest/core-client`

### Issues associated with this PR

- Fix #31349

### Describe the problem that is addressed by this PR

We generate RLCs that allow for path parameters to be `number`. The
change for `allowReserved` assumed that path parameters could only be
`string`, causing number parameters to not be serialized properly. This
PR fixes that assumption.

### What are the possible designs available to address the problem? If
there are more than one possible design, why was the one in this PR
chosen?


### Are there test cases added in this PR? _(If not, why?)_

Added a test to check for a number path parameter

### Provide a list of related PRs _(if any)_

- #31058

sdk/core/core-client-rest/CHANGELOG.md

@@ -8,6 +8,8 @@
 
 ### Bugs Fixed
 
+- Allow `number` path parameters. PR [#31352](https://github.com/Azure/azure-sdk-for-js/pull/31352/files)
+
 ### Other Changes
 
 ## 2.3.0 (2024-10-03)

sdk/core/core-client-rest/review/core-client.api.md

@@ -138,15 +138,15 @@ export interface OperationRequestOptions {
 
 // @public
 export type PathParameters<TRoute extends string> = TRoute extends `${infer _Head}/{${infer _Param}}${infer Tail}` ? [
-pathParameter: string | PathParameterWithOptions,
+pathParameter: string | number | PathParameterWithOptions,
 ...pathParameters: PathParameters<Tail>
 ] : [
 ];
 
 // @public
 export interface PathParameterWithOptions {
     allowReserved?: boolean;
-    value: string;
+    value: string | number;
 }
 
 // @public

sdk/core/core-client-rest/src/common.ts

@@ -398,7 +398,10 @@ export type PathParameters<
     // additional parameters we can call RouteParameters recursively on the Tail to match the remaining parts,
     // in case the Tail has more parameters, it will return a tuple with the parameters found in tail.
     // We spread the second path params to end up with a single dimension tuple at the end.
-    [pathParameter: string | PathParameterWithOptions, ...pathParameters: PathParameters<Tail>]
+    [
+      pathParameter: string | number | PathParameterWithOptions,
+      ...pathParameters: PathParameters<Tail>,
+    ]
   : // When the path doesn't match the template, it means that we have no path parameters so we return
     // an empty tuple.
     [];
@@ -438,7 +441,7 @@ export interface PathParameterWithOptions {
   /**
    * The value of the parameter.
    */
-  value: string;
+  value: string | number;
 
   /**
    * Whether to allow for reserved characters in the value. If set to true, special characters such as '/' in the parameter's value will not be URL encoded.

sdk/core/core-client-rest/src/urlHelpers.ts

@@ -54,7 +54,7 @@ function isQueryParameterWithOptions(x: unknown): x is QueryParameterWithOptions
 export function buildRequestUrl(
   endpoint: string,
   routePath: string,
-  pathParameters: (string | PathParameterWithOptions)[],
+  pathParameters: (string | number | PathParameterWithOptions)[],
   options: RequestParameters = {},
 ): string {
   if (routePath.startsWith("https://") || routePath.startsWith("http://")) {
@@ -187,19 +187,18 @@ export function buildBaseUrl(endpoint: string, options: RequestParameters): stri
 
 function buildRoutePath(
   routePath: string,
-  pathParameters: (string | PathParameterWithOptions)[],
+  pathParameters: (string | number | PathParameterWithOptions)[],
   options: RequestParameters = {},
 ): string {
   for (const pathParam of pathParameters) {
-    const allowReserved =
-      typeof pathParam === "string" ? false : (pathParam?.allowReserved ?? false);
-    let value = typeof pathParam === "string" ? pathParam : pathParam?.value;
+    const allowReserved = typeof pathParam === "object" && (pathParam.allowReserved ?? false);
+    let value = typeof pathParam === "object" ? pathParam.value : pathParam;
 
     if (!options.skipUrlEncoding && !allowReserved) {
       value = encodeURIComponent(value);
     }
 
-    routePath = routePath.replace(/\{\w+\}/, value);
+    routePath = routePath.replace(/\{\w+\}/, String(value));
   }
   return routePath;
 }

sdk/core/core-client-rest/test/urlHelpers.spec.ts

@@ -19,6 +19,12 @@ describe("urlHelpers", () => {
     assert.equal(result, `https://example.org/foo/one`);
   });
 
+  it("should append number path parameters", () => {
+    const result = buildRequestUrl(mockBaseUrl, "/foo/{id}", [12345]);
+
+    assert.equal(result, "https://example.org/foo/12345");
+  });
+
   it("should append path, fill path parameters and append query parameters", () => {
     const result = buildRequestUrl(mockBaseUrl, "/foo/{id}", ["one"], {
       queryParameters: { foo: "1", bar: "two" },