feat: StringList handling in default parameter processor

src/Amazon.Extensions.Configuration.SystemsManager/DefaultParameterProcessor.cs

@@ -16,6 +16,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Amazon.SimpleSystemsManagement;
 using Amazon.SimpleSystemsManagement.Model;
 using Microsoft.Extensions.Configuration;
 
@@ -42,16 +43,33 @@ public virtual string GetKey(Parameter parameter, string path)
 
         public virtual string GetValue(Parameter parameter, string path) => parameter.Value;
 
+        private IEnumerable<KeyValuePair<string, string>> ParseStringList(Parameter parameter, string path)
+        {
+            // Items in a StringList must be separated by a comma (,).
+            // You can't use other punctuation or special characters to escape items in the list.
+            // If you have a parameter value that requires a comma, then use the String type.
+            // https://docs.aws.amazon.com/systems-manager/latest/userguide/param-create-cli.html#param-create-cli-stringlist
+            return parameter.Value.Split(",").Select((value, idx) =>
+                new KeyValuePair<string, string>($"{GetKey(parameter, path)}:{idx}", value));
+        }
+
         public virtual IDictionary<string, string> ProcessParameters(IEnumerable<Parameter> parameters, string path)
         {
-            return parameters
-                .Where(parameter => IncludeParameter(parameter, path))
-                .Select(parameter => new
+            var result = new List<KeyValuePair<string, string>>();
+            foreach (var parameter in parameters.Where(parameter => IncludeParameter(parameter, path)))
+            {
+                if (parameter.Type == ParameterType.StringList)
                 {
-                    Key = GetKey(parameter, path),
-                    Value = GetValue(parameter, path)
-                })
-                .ToDictionary(parameter => parameter.Key, parameter => parameter.Value, StringComparer.OrdinalIgnoreCase);
+                    result.AddRange(ParseStringList(parameter, path));
+                }
+                else
+                {
+                    result.Add(new KeyValuePair<string, string>(GetKey(parameter, path), GetValue(parameter, path)));
+                }
+            }
+
+            return result.ToDictionary(parameter => parameter.Key, parameter => parameter.Value,
+                StringComparer.OrdinalIgnoreCase);
         }
     }
 }

test/Amazon.Extensions.Configuration.SystemsManager.Tests/DefaultParameterProcessorTests.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using Amazon.SimpleSystemsManagement;
 using Amazon.SimpleSystemsManagement.Model;
 using Moq;
 using Xunit;
@@ -32,6 +33,29 @@ public void ProcessParametersTest()
             Assert.All(data, item => Assert.Equal(item.Value, item.Key));
         }
 
+        [Fact]
+        public void ProcessParametersStringListTest()
+        {
+            var parameters = new List<Parameter>
+            {
+                new Parameter {Name = "/string-list/single", Value = "p1", Type = ParameterType.StringList},
+                new Parameter {Name = "/string-list/multiple", Value = "p1,p2,p3", Type = ParameterType.StringList},
+                new Parameter {Name = "/string-list/empty", Value = "", Type = ParameterType.StringList},
+            };
+
+            const string path = "/string-list";
+
+            var data = _parameterProcessor.ProcessParameters(parameters, path);
+
+            Assert.Equal(5, data.Keys.Count);
+            Assert.Equal("p1", data["single:0"]);
+            Assert.Equal("p1", data["multiple:0"]);
+            Assert.Equal("p2", data["multiple:1"]);
+            Assert.Equal("p3", data["multiple:2"]);
+            Assert.Equal("", data["empty:0"]);
+        }
+
+
         [Fact]
         public void ProcessParametersRootTest()
         {