add test and documentation for multi-value field verification (#310)

Author: duke8253

README.md

@@ -1141,6 +1141,32 @@ proxy-response:
     - [ x-test-trailer-2, { value: two, as: equal } ]
 ```
 
+To perform multi-value field verification, a specific format must be adhered to.
+This format involves specifying each value within a sequence, ensuring that each
+value is individually verified according to the defined rules.
+
+Be aware that field verification is order sensitive. That is, the field values
+will be verified in the order that they are specified in the verification rule.
+
+See example below, value `B1` and `B2` are specified in the same order in the
+header fields and verification rule:
+
+```YAML
+server-response:
+  headers:
+    fields:
+    - [:status, 200]
+    - [Content-Type, text/html]
+    - [Content-Length, '11']
+    - [Set-Cookie, "B1=abc"]
+    - [Set-Cookie, "B2=abc"]
+
+proxy-response:
+  headers:
+    fields:
+    - [Set-Cookie, { value: [B1=, B2=] , as: contains }]
+```
+
 ### URL Verification
 
 In a manner similar to field verification described above, a mechanism exists

test/autests/gold_tests/field_verification/field_verification.test.py

@@ -159,3 +159,20 @@
 
 client.ReturnCode = 1
 server.ReturnCode = 1
+
+# Test 4: Verify field verification works with multi-value fields
+r = Test.AddTestRun("Verify field verification works with multi-value fields")
+client = r.AddClientProcess("client4", "replay_files/multi_value.yaml")
+server = r.AddServerProcess("server4", "replay_files/multi_value.yaml")
+proxy = r.AddProxyProcess(
+    "proxy4",
+    listen_port=client.Variables.https_port,
+    server_port=server.Variables.https_port,
+    use_ssl=True, use_http2_to_2=True)
+
+client.Streams.stdout += Testers.ContainsExpression(
+    'Contains Success: Key: "1", Field Name: "set-cookie", Required Values: "B1=" "B2=", Received Values: "B1=abc" "B2=abc"',
+    "Verification should be happy with the set coookies.")
+
+client.ReturnCode = 0
+server.ReturnCode = 0

test/autests/gold_tests/field_verification/replay_files/multi_value.yaml

@@ -0,0 +1,44 @@
+meta:
+  version: '1.0'
+sessions:
+- protocol:
+  - name: http
+    version: 2
+  - name: tls
+    sni: test_sni
+  - name: tcp
+  - name: ip
+    version: 4
+  transactions:
+  - client-request:
+      headers:
+        fields:
+        - [:method, POST]
+        - [:scheme, https]
+        - [:authority, example.data.com]
+        - [:path, /a/path]
+        - [Content-Type, text/html]
+        - [Content-Length, '11']
+        - [uuid, 1]
+      content:
+        encoding: plain
+        data: client_test
+        size: 11
+
+    server-response:
+      headers:
+        fields:
+        - [:status, 200]
+        - [Content-Type, text/html]
+        - [Content-Length, '11']
+        - [Set-Cookie, "B1=abc"]
+        - [Set-Cookie, "B2=abc"]
+      content:
+        encoding: plain
+        data: server_test
+        size: 11
+
+    proxy-response:
+      headers:
+        fields:
+        - [Set-Cookie, { value: [B1=, B2=] , as: contains }]