Update code to use C# 7 features;

Add explicit validations for connection/transaction to implement JobStorageConnection/JobStorageTransaction;
Update unit tests

appveyor.yml

@@ -1,4 +1,4 @@
-version: 1.3.10-{build}
+version: 1.4.0-{build}
 
 os: Visual Studio 2017
 

src/Hangfire.Console/Dashboard/ConsoleDispatcher.cs

@@ -16,10 +16,7 @@ internal class ConsoleDispatcher : IDashboardDispatcher
 
         public ConsoleDispatcher(ConsoleOptions options)
         {
-            if (options == null)
-                throw new ArgumentNullException(nameof(options));
-
-            _options = options;
+            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public Task Dispatch(DashboardContext context)
@@ -32,8 +29,7 @@ public Task Dispatch(DashboardContext context)
             var startArg = context.Request.GetQuery("start");
 
             // try to parse offset at which we should start returning requests
-            int start;
-            if (string.IsNullOrEmpty(startArg) || !int.TryParse(startArg, out start))
+            if (string.IsNullOrEmpty(startArg) || !int.TryParse(startArg, out var start))
             {
                 // if not provided or invalid, fetch records from the very start
                 start = 0;

src/Hangfire.Console/Dashboard/ConsoleRenderer.cs

@@ -3,7 +3,6 @@
 using Hangfire.Console.Storage;
 using Hangfire.Dashboard;
 using Hangfire.States;
-using Hangfire.Storage;
 using System;
 using System.Collections.Generic;
 using System.Globalization;
@@ -52,7 +51,7 @@ public static void RenderText(StringBuilder buffer, string text)
                     buffer.Append(Helper.HtmlEncode(text.Substring(start, m.Index - start)));
                 }
 
-                string schema = "";
+                var schema = "";
                 if (!m.Groups["schema"].Success)
                 {
                     // force schema for links without one (like www.google.com)
@@ -192,8 +191,7 @@ private static IEnumerable<ConsoleLine> ReadLines(IConsoleStorage storage, Conso
 
                         if (progressBars != null)
                         {
-                            ConsoleLine prev;
-                            if (progressBars.TryGetValue(entry.Message, out prev))
+                            if (progressBars.TryGetValue(entry.Message, out var prev))
                             {
                                 prev.ProgressValue = entry.ProgressValue;
                                 prev.TextColor = entry.TextColor;

src/Hangfire.Console/Dashboard/DynamicCssDispatcher.cs

@@ -14,10 +14,7 @@ internal class DynamicCssDispatcher : IDashboardDispatcher
 
         public DynamicCssDispatcher(ConsoleOptions options)
         {
-            if (options == null)
-                throw new ArgumentNullException(nameof(options));
-
-            _options = options;
+            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public Task Dispatch(DashboardContext context)

src/Hangfire.Console/Dashboard/DynamicJsDispatcher.cs

@@ -14,20 +14,17 @@ internal class DynamicJsDispatcher : IDashboardDispatcher
 
         public DynamicJsDispatcher(ConsoleOptions options)
         {
-            if (options == null)
-                throw new ArgumentNullException(nameof(options));
-
-            _options = options;
+            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public Task Dispatch(DashboardContext context)
         {
             var builder = new StringBuilder();
 
-            builder.Append(@"(function (hangFire) {")
-                   .Append("hangFire.config = hangFire.config || {};")
-                   .AppendFormat("hangFire.config.consolePollInterval = {0};", _options.PollInterval)
-                   .AppendFormat("hangFire.config.consolePollUrl = '{0}/console/';", context.Request.PathBase)
+            builder.Append(@"(function (hangfire) {")
+                   .Append("hangfire.config = hangfire.config || {};")
+                   .AppendFormat("hangfire.config.consolePollInterval = {0};", _options.PollInterval)
+                   .AppendFormat("hangfire.config.consolePollUrl = '{0}/console/';", context.Request.PathBase)
                    .Append("})(window.Hangfire = window.Hangfire || {});")
                    .AppendLine();
 

src/Hangfire.Console/Dashboard/ProcessingStateRenderer.cs

@@ -14,14 +14,12 @@ namespace Hangfire.Console.Dashboard
     /// </summary>
     internal class ProcessingStateRenderer
     {
+        // ReSharper disable once NotAccessedField.Local
         private readonly ConsoleOptions _options;
 
         public ProcessingStateRenderer(ConsoleOptions options)
         {
-            if (options == null)
-                throw new ArgumentNullException(nameof(options));
-
-            _options = options;
+            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public NonEscapedString Render(HtmlHelper helper, IDictionary<string, string> stateData)

src/Hangfire.Console/EnumerableExtensions.cs

@@ -20,13 +20,13 @@ public static class EnumerableExtensions
         /// <param name="count">Item count</param>
         public static IEnumerable<T> WithProgress<T>(this IEnumerable<T> enumerable, IProgressBar progressBar, int count = -1)
         {
-            if (enumerable is ICollection<T>)
+            if (enumerable is ICollection<T> collection)
             {
-                count = ((ICollection<T>)enumerable).Count;
+                count = collection.Count;
             }
-            else if (enumerable is IReadOnlyCollection<T>)
+            else if (enumerable is IReadOnlyCollection<T> readOnlyCollection)
             {
-                count = ((IReadOnlyCollection<T>)enumerable).Count;
+                count = readOnlyCollection.Count;
             }
             else if (count < 0)
             {
@@ -44,9 +44,9 @@ public static IEnumerable<T> WithProgress<T>(this IEnumerable<T> enumerable, IPr
         /// <param name="count">Item count</param>
         public static IEnumerable WithProgress(this IEnumerable enumerable, IProgressBar progressBar, int count = -1)
         {
-            if (enumerable is ICollection)
+            if (enumerable is ICollection collection)
             {
-                count = ((ICollection)enumerable).Count;
+                count = collection.Count;
             }
             else if (count < 0)
             {

src/Hangfire.Console/Monitoring/ConsoleApi.cs

@@ -44,8 +44,7 @@ public IList<LineDto> GetLines(string jobId, DateTime timestamp, LineType type =
 
                         if (progressBars != null)
                         {
-                            ProgressBarDto prev;
-                            if (progressBars.TryGetValue(entry.Message, out prev))
+                            if (progressBars.TryGetValue(entry.Message, out var prev))
                             {
                                 prev.Progress = entry.ProgressValue.Value;
                                 prev.Color = entry.TextColor;

src/Hangfire.Console/Monitoring/ProgressBarDto.cs

@@ -12,6 +12,8 @@ public class ProgressBarDto : LineDto
         internal ProgressBarDto(ConsoleLine line, DateTime referenceTimestamp) : base(line, referenceTimestamp)
         {
             Id = int.Parse(line.Message, CultureInfo.InvariantCulture);
+            Name = line.ProgressName;
+            // ReSharper disable once PossibleInvalidOperationException
             Progress = line.ProgressValue.Value;
         }
 
@@ -23,6 +25,11 @@ internal ProgressBarDto(ConsoleLine line, DateTime referenceTimestamp) : base(li
         /// </summary>
         public int Id { get; }
 
+        /// <summary>
+        /// Returns optional name for a progress bar
+        /// </summary>
+        public string Name { get; }
+
         /// <summary>
         /// Returns progress value for a progress bar
         /// </summary>

src/Hangfire.Console/Progress/DefaultProgressBar.cs

@@ -18,12 +18,10 @@ internal class DefaultProgressBar : IProgressBar
 
         internal DefaultProgressBar(ConsoleContext context, string progressBarId, string name, string color)
         {
-            if (context == null)
-                throw new ArgumentNullException(nameof(context));
             if (string.IsNullOrEmpty(progressBarId))
                 throw new ArgumentNullException(nameof(progressBarId));
 
-            _context = context;
+            _context = context ?? throw new ArgumentNullException(nameof(context));
             _progressBarId = progressBarId;
             _name = name;
             _color = color;
@@ -42,6 +40,7 @@ public void SetValue(double value)
             if (value < 0 || value > 100)
                 throw new ArgumentOutOfRangeException(nameof(value), "Value should be in range 0..100");
 
+            // ReSharper disable once CompareOfFloatsByEqualityOperator
             if (Interlocked.Exchange(ref _value, value) == value) return;
 
             _context.AddLine(new ConsoleLine() { Message = _progressBarId, ProgressName = _name, ProgressValue = value, TextColor = _color });

src/Hangfire.Console/Progress/IProgressBar.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-
-namespace Hangfire.Console.Progress
+namespace Hangfire.Console.Progress
 {
     /// <summary>
     /// Progress bar line inside console.

src/Hangfire.Console/Progress/ProgressEnumerable.cs

@@ -15,15 +15,11 @@ internal class ProgressEnumerable : IEnumerable
 
         public ProgressEnumerable(IEnumerable enumerable, IProgressBar progressBar, int count)
         {
-            if (enumerable == null)
-                throw new ArgumentNullException(nameof(enumerable));
-            if (progressBar == null)
-                throw new ArgumentNullException(nameof(progressBar));
             if (count < 0)
                 throw new ArgumentOutOfRangeException(nameof(count));
 
-            _enumerable = enumerable;
-            _progressBar = progressBar;
+            _enumerable = enumerable ?? throw new ArgumentNullException(nameof(enumerable));
+            _progressBar = progressBar ?? throw new ArgumentNullException(nameof(progressBar));
             _count = count;
         }
 
@@ -98,15 +94,11 @@ internal class ProgressEnumerable<T> : IEnumerable<T>
 
         public ProgressEnumerable(IEnumerable<T> enumerable, IProgressBar progressBar, int count)
         {
-            if (enumerable == null)
-                throw new ArgumentNullException(nameof(enumerable));
-            if (progressBar == null)
-                throw new ArgumentNullException(nameof(progressBar));
             if (count < 0)
                 throw new ArgumentOutOfRangeException(nameof(count));
 
-            _enumerable = enumerable;
-            _progressBar = progressBar;
+            _enumerable = enumerable ?? throw new ArgumentNullException(nameof(enumerable));
+            _progressBar = progressBar ?? throw new ArgumentNullException(nameof(progressBar));
             _count = count;
         }
 

src/Hangfire.Console/Serialization/ConsoleId.cs

@@ -9,7 +9,7 @@ internal class ConsoleId : IEquatable<ConsoleId>
     {
         private static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
-        private string _cachedString = null;
+        private string _cachedString;
 
         /// <summary>
         /// Job identifier
@@ -68,24 +68,21 @@ public static ConsoleId Parse(string value)
             // Timestamp is serialized in reverse order for better randomness!
 
             long timestamp = 0;
-            for (int i = 10; i >= 0; i--)
+            for (var i = 10; i >= 0; i--)
             {
                 var c = value[i] | 0x20;
 
                 var x = (c >= '0' && c <= '9') ? (c - '0') : (c >= 'a' && c <= 'f') ? (c - 'a' + 10) : -1;
                 if (x == -1)
                     throw new ArgumentException("Invalid value", nameof(value));
 
-                timestamp = (timestamp << 4) | (long)x;
+                timestamp = (timestamp << 4) + x;
             }
 
             return new ConsoleId(value.Substring(11), timestamp) { _cachedString = value };
         }
 
-        /// <summary>
-        /// Determines if this instance is equal to <paramref name="other"/> instance.
-        /// </summary>
-        /// <param name="other">Other instance</param>
+        /// <inheritdoc />
         public bool Equals(ConsoleId other)
         {
             if (ReferenceEquals(other, null)) return false;
@@ -103,7 +100,7 @@ public override string ToString()
                 var buffer = new char[11 + JobId.Length];
 
                 var timestamp = Timestamp;
-                for (int i = 0; i < 11; i++, timestamp >>= 4)
+                for (var i = 0; i < 11; i++, timestamp >>= 4)
                 {
                     var c = timestamp & 0x0F;
                     buffer[i] = (c < 10) ? (char)(c + '0') : (char)(c - 10 + 'a');
@@ -118,15 +115,9 @@ public override string ToString()
         }
 
         /// <inheritdoc />
-        public override bool Equals(object obj)
-        {
-            return Equals(obj as ConsoleId);
-        }
+        public override bool Equals(object obj) => Equals(obj as ConsoleId);
 
         /// <inheritdoc />
-        public override int GetHashCode()
-        {
-            return (JobId.GetHashCode() * 17) ^ Timestamp.GetHashCode();
-        }
+        public override int GetHashCode() => (JobId.GetHashCode() * 17) ^ Timestamp.GetHashCode();
     }
 }

src/Hangfire.Console/Serialization/ConsoleLine.cs

@@ -22,18 +22,11 @@ internal class ConsoleLine
         [JsonProperty("s", Required = Required.Always)]
         public string Message { get; set; }
 
-        [JsonIgnore]
-        private string _textColor;
-
         /// <summary>
         /// Text color for this message
         /// </summary>
         [JsonProperty("c", DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string TextColor
-        {
-            get { return _textColor; }
-            set { _textColor = string.IsNullOrEmpty(value) ? null : value; }
-        }
+        public string TextColor { get; set; }
 
         /// <summary>
         /// Value update for a progress bar

src/Hangfire.Console/Server/ConsoleContext.cs

@@ -34,13 +34,8 @@ public static ConsoleContext FromPerformContext(PerformContext context)
 
         public ConsoleContext(ConsoleId consoleId, IConsoleStorage storage)
         {
-            if (consoleId == null)
-                throw new ArgumentNullException(nameof(consoleId));
-            if (storage == null)
-                throw new ArgumentNullException(nameof(storage));
-
-            _consoleId = consoleId;
-            _storage = storage;
+            _consoleId = consoleId ?? throw new ArgumentNullException(nameof(consoleId));
+            _storage = storage ?? throw new ArgumentNullException(nameof(storage));
 
             _lastTimeOffset = 0;
             _nextProgressBarId = 0;
@@ -87,15 +82,15 @@ public IProgressBar WriteProgressBar(string name, double value, ConsoleTextColor
 
             return progressBar;
         }
-
+        
         public void Expire(TimeSpan expireIn)
         {
             _storage.Expire(_consoleId, expireIn);
         }
 
         public void FixExpiration()
         {
-            TimeSpan ttl = _storage.GetConsoleTtl(_consoleId);
+            var ttl = _storage.GetConsoleTtl(_consoleId);
             if (ttl <= TimeSpan.Zero)
             {
                 // ConsoleApplyStateFilter not called yet, or current job state is not final.

src/Hangfire.Console/Server/ConsoleServerFilter.cs

@@ -16,10 +16,7 @@ internal class ConsoleServerFilter : IServerFilter
 
         public ConsoleServerFilter(ConsoleOptions options)
         {
-            if (options == null)
-                throw new ArgumentNullException(nameof(options));
-
-            _options = options;
+            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public void OnPerforming(PerformingContext filterContext)

src/Hangfire.Console/States/ConsoleApplyStateFilter.cs

@@ -14,10 +14,7 @@ internal class ConsoleApplyStateFilter : IApplyStateFilter
 
         public ConsoleApplyStateFilter(ConsoleOptions options)
         {
-            if (options == null)
-                throw new ArgumentNullException(nameof(options));
-
-            _options = options;
+            _options = options ?? throw new ArgumentNullException(nameof(options));
         }
 
         public void OnStateApplied(ApplyStateContext context, IWriteOnlyTransaction transaction)

src/Hangfire.Console/Storage/ConsoleExpirationTransaction.cs

@@ -10,10 +10,7 @@ internal class ConsoleExpirationTransaction : IConsoleExpirationTransaction
 
         public ConsoleExpirationTransaction(JobStorageTransaction transaction)
         {
-            if (transaction == null)
-                throw new ArgumentNullException(nameof(transaction));
-
-            _transaction = transaction;
+            _transaction = transaction ?? throw new ArgumentNullException(nameof(transaction));
         }
 
         public void Dispose()