apply minor improvements (#1844)

Author: davidmrdavid

test/Common/DurableTaskEndToEndTests.cs

@@ -584,9 +584,9 @@ await TestHelpers.WaitUntilTrue(
                      * as there are JSON (each of which has 1 EventTimestamp field), then we know that
                      * Exceptions must have had their newlines removed.
                      */
-                    string[] lines = TestHelpers.WriteSafeReadAllLines(LinuxAppServiceLogger.LoggingPath);
+                    List<string> lines = TestHelpers.WriteSafeReadAllLines(LinuxAppServiceLogger.LoggingPath);
                     int countTimeStampCols = Regex.Matches(string.Join("", lines), "\"EventTimestamp\":").Count;
-                    return lines.Length == countTimeStampCols;
+                    return lines.Count == countTimeStampCols;
                 },
                 conditionDescription: "Log file exists and newlines are removed from exceptions",
                 timeout: TimeSpan.FromSeconds(65)); // enabling at least 2 file-buffer flushes (happen every 30 seconds)
@@ -644,7 +644,7 @@ await TestHelpers.WaitUntilTrue(
             await TestHelpers.WaitUntilTrue(
                 predicate: () =>
                 {
-                    string[] lines = TestHelpers.WriteSafeReadAllLines(LinuxAppServiceLogger.LoggingPath);
+                    List<string> lines = TestHelpers.WriteSafeReadAllLines(LinuxAppServiceLogger.LoggingPath);
                     IEnumerable<JObject> jsons = lines.Select(line => JObject.Parse(line));
 
                     if (!jsons.All(json => TestHelpers.IsValidJSONLog(json)))

test/Common/TestHelpers.cs

@@ -282,10 +282,10 @@ public static bool IsValidJSONLog(JObject json)
                 "Pid",
                 "Tid",
             };
-            List<string> keys = json.Properties().Select(p => p.Name).ToList();
+
             foreach (string expectedKey in expectedKeys)
             {
-                if (!keys.Contains(expectedKey))
+                if (!json.TryGetValue(expectedKey, out _))
                 {
                     return false;
                 }
@@ -299,7 +299,7 @@ public static bool IsValidJSONLog(JObject json)
         /// </summary>
         /// <param name="path">The file's path.</param>
         /// <returns>An array of each line in the file.</returns>
-        public static string[] WriteSafeReadAllLines(string path)
+        public static List<string> WriteSafeReadAllLines(string path)
         {
             /* A method like File.ReadAllLines cannot open a file that is open for writing by another process
              * This is due to the File.ReadAllLines  not opening the process with ReadWrite permissions.
@@ -316,7 +316,7 @@ public static string[] WriteSafeReadAllLines(string path)
                     file.Add(streamReader.ReadLine());
                 }
 
-                return file.ToArray();
+                return file;
             }
         }