test: indifference to comma separated header spacing

Author: kuhe

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/HttpProtocolTestGenerator.java

@@ -71,6 +71,7 @@
 import software.amazon.smithy.utils.IoUtils;
 import software.amazon.smithy.utils.MapUtils;
 import software.amazon.smithy.utils.Pair;
+import software.amazon.smithy.utils.SetUtils;
 import software.amazon.smithy.utils.SmithyInternalApi;
 
 /**
@@ -91,6 +92,9 @@ public final class HttpProtocolTestGenerator implements Runnable {
 
     private static final Logger LOGGER = Logger.getLogger(HttpProtocolTestGenerator.class.getName());
     private static final String TEST_CASE_FILE_TEMPLATE = "test/functional/%s.spec.ts";
+    private static final Set<String> IGNORE_COMMA_SPACING = SetUtils.of(
+        "content-encoding"
+    );
 
     private final TypeScriptSettings settings;
     private final Model model;
@@ -517,7 +521,17 @@ private void writeHttpHeaderAssertions(HttpMessageTestCase testCase) {
         testCase.getHeaders().forEach((header, value) -> {
             header = header.toLowerCase();
             writer.write("expect(r.headers[$S]).toBeDefined();", header);
-            writer.write("expect(r.headers[$S]).toBe($S);", header, value);
+            if (IGNORE_COMMA_SPACING.contains(header) && value.contains(",")) {
+                writer.write("""
+                    expect(
+                      r.headers[$S].replaceAll(", ", ",")
+                    ).toBe(
+                      $S.replaceAll(", ", ",")
+                    );
+                    """, header, value);
+            } else {
+                writer.write("expect(r.headers[$S]).toBe($S);", header, value);
+            }
         });
         writer.write("");
     }