Add docs for all the analyzers

docs/Rules/EPC11.md

@@ -0,0 +1,57 @@
+# EPC11 - Suspicious equality implementation
+
+This analyzer detects suspicious implementations of `Equals` methods that may not be working as intended.
+
+## Description
+
+The analyzer warns when an `Equals` method implementation appears suspicious, typically when the method doesn't use any instance members or compares against other instances properly.
+
+## Code that triggers the analyzer
+
+```csharp
+public class MyClass
+{
+    public override bool Equals(object obj)
+    {
+        // Suspicious: only using static members or not using 'this' instance
+        return SomeStaticProperty == 42;
+    }
+}
+```
+
+```csharp
+public class Person
+{
+    public string Name { get; set; }
+
+    public override bool Equals(object obj)
+    {
+        // Suspicious: parameter 'obj' is never used
+        return this.Name == "test";
+    }
+}
+```
+
+## How to fix
+
+Implement `Equals` method properly by:
+
+1. Using the parameter that's passed in
+2. Checking instance members against the other object's members
+3. Following the standard equality pattern
+
+```csharp
+public class Person
+{
+    public string Name { get; set; }
+
+    public override bool Equals(object obj)
+    {
+        if (obj is Person other)
+        {
+            return this.Name == other.Name;
+        }
+        return false;
+    }
+}
+```

docs/Rules/EPC12.md

@@ -0,0 +1,41 @@
+# EPC12 - Suspicious exception handling: only the 'Message' property is observed in the catch block
+
+This analyzer detects catch blocks where only the `Message` property of an exception is used, which often indicates incomplete exception handling.
+
+## Description
+
+The analyzer warns when a catch block only accesses the `Message` property of an exception without observing the exception object itself or its other important properties like `InnerException`. This is suspicious because the `Message` property often contains generic information, while the actual useful data is in the exception object or its inner exceptions.
+
+## Code that triggers the analyzer
+
+```csharp
+try
+{
+    // Some risky operation
+    SomeMethod();
+}
+catch (Exception ex)
+{
+    // Only using ex.Message - this triggers the warning
+    Console.WriteLine(ex.Message);
+}
+```
+
+
+## How to fix
+
+Use the full exception object or access additional properties like `InnerException`:
+
+```csharp
+try
+{
+    SomeMethod();
+}
+catch (Exception ex)
+{
+    // Log the full exception object
+    Console.WriteLine(ex.ToString());
+    // Or access the exception object directly
+    LogException(ex);
+}
+```

docs/Rules/EPC13.md

@@ -0,0 +1,64 @@
+# EPC13 - Suspiciously unobserved result
+
+This analyzer detects when method return values that should typically be observed are being ignored.
+
+## Description
+
+The analyzer warns when the result of a method call is not being used, particularly for methods that return important values that should be observed. This helps catch cases where developers might have forgotten to use the return value of a method.
+
+## Code that triggers the analyzer
+
+```csharp
+public class Example
+{
+    public void ProcessData()
+    {
+        // Return value is ignored - this triggers the warning
+        GetImportantValue();
+
+        // String methods return new strings but result is ignored
+        "hello".ToUpper();
+
+        // Collection methods that return new collections
+        list.Where(x => x > 0);
+    }
+
+    public string GetImportantValue()
+    {
+        return "important data";
+    }
+}
+```
+
+## How to fix
+
+Observe (use) the return values:
+
+```csharp
+public class Example
+{
+    public void ProcessData()
+    {
+        // Store the result in a variable
+        var importantValue = GetImportantValue();
+
+        // Use the result directly
+        var upperText = "hello".ToUpper();
+        Console.WriteLine(upperText);
+
+        // Chain operations or store result
+        var filteredList = list.Where(x => x > 0).ToList();
+    }
+
+    public string GetImportantValue()
+    {
+        return "important data";
+    }
+}
+```
+
+If you intentionally want to ignore the result, you can use discard:
+
+```csharp
+_ = GetImportantValue(); // Explicitly ignore the result
+```

docs/Rules/EPC14.md

@@ -0,0 +1,36 @@
+# EPC14 - ConfigureAwait(false) call is redundant
+
+This analyzer detects redundant calls to `ConfigureAwait(false)` when the assembly is configured not to require them.
+
+## Description
+
+The analyzer provides information (not a warning) when `ConfigureAwait(false)` calls are redundant because the assembly has been configured to not capture the synchronization context automatically. This helps clean up unnecessary code.
+
+## Code that triggers the analyzer
+
+```csharp
+public async Task ProcessAsync()
+{
+    // ConfigureAwait(false) is redundant when assembly is configured for it
+    await SomeAsyncMethod().ConfigureAwait(false);
+
+    // This is also redundant
+    var result = await GetDataAsync().ConfigureAwait(false);
+}
+```
+
+## How to fix
+
+Remove the redundant `ConfigureAwait(false)` calls:
+
+```csharp
+public async Task ProcessAsync()
+{
+    // ConfigureAwait(false) behavior is already configured at assembly level
+    await SomeAsyncMethod();
+
+    var result = await GetDataAsync();
+}
+```
+
+Note: This rule only applies when your assembly is configured to not capture synchronization context by default. The configuration is typically done through project settings or attributes.

docs/Rules/EPC15.md

@@ -0,0 +1,46 @@
+# EPC15 - ConfigureAwait(false) must be used
+
+This analyzer detects missing `ConfigureAwait(false)` calls when the assembly is configured to require them.
+
+## Description
+
+The analyzer warns when `ConfigureAwait(false)` should be used but is missing. This typically applies to library code where you want to avoid deadlocks by not capturing the synchronization context.
+
+## Code that triggers the analyzer
+
+```csharp
+public async Task ProcessAsync()
+{
+    // Missing ConfigureAwait(false) - this triggers the warning
+    await SomeAsyncMethod();
+
+    // Also missing ConfigureAwait(false)
+    var result = await GetDataAsync();
+}
+```
+
+## How to fix
+
+Add `ConfigureAwait(false)` to all await expressions:
+
+```csharp
+public async Task ProcessAsync()
+{
+    // Add ConfigureAwait(false) to avoid capturing sync context
+    await SomeAsyncMethod().ConfigureAwait(false);
+
+    var result = await GetDataAsync().ConfigureAwait(false);
+}
+```
+
+## When to use ConfigureAwait(false)
+
+Use `ConfigureAwait(false)` in:
+- Library code that doesn't need to return to the original synchronization context
+- Background processing code
+- Code that doesn't interact with UI elements
+
+Don't use `ConfigureAwait(false)` in:
+- UI event handlers
+- Controller actions that need to return to the original context
+- Code that accesses UI elements after the await

docs/Rules/EPC16.md

@@ -0,0 +1,64 @@
+# EPC16 - Awaiting a result of a null-conditional expression will cause NullReferenceException
+
+This analyzer detects dangerous patterns where awaiting the result of a null-conditional operator can cause a `NullReferenceException`.
+
+## Description
+
+The analyzer warns when code awaits the result of a null-conditional expression. When the left-hand side of the null-conditional operator is null, the expression returns null, and awaiting null will throw a `NullReferenceException`.
+
+## Code that triggers the analyzer
+
+```csharp
+public async Task ProcessAsync()
+{
+    SomeService service = GetService(); // might return null
+
+    // Dangerous: if service is null, this returns null, and awaiting null throws NRE
+    await service?.ProcessAsync();
+}
+```
+
+```csharp
+public async Task<string> GetDataAsync()
+{
+    var client = GetHttpClient(); // might return null
+
+    // This will throw NRE if client is null
+    return await client?.GetStringAsync("http://example.com");
+}
+```
+
+## How to fix
+
+Check for null before awaiting, or use proper null handling:
+
+```csharp
+public async Task ProcessAsync()
+{
+    SomeService service = GetService();
+
+    // Option 1: Check for null first
+    if (service != null)
+    {
+        await service.ProcessAsync();
+    }
+
+    // Option 2: Use null-coalescing with Task.CompletedTask
+    await (service?.ProcessAsync() ?? Task.CompletedTask);
+}
+```
+
+```csharp
+public async Task<string> GetDataAsync()
+{
+    var client = GetHttpClient();
+
+    // Check for null before using
+    if (client == null)
+    {
+        return null; // or throw, or return default value
+    }
+
+    return await client.GetStringAsync("http://example.com");
+}
+```

docs/Rules/EPC17.md

@@ -0,0 +1,61 @@
+# EPC17 - Avoid async-void delegates
+
+This analyzer detects the use of async void delegates, which can cause application crashes due to unhandled exceptions.
+
+## Description
+
+The analyzer warns against using async void delegates. Unlike async void methods (which should only be used for event handlers), async void delegates are particularly dangerous because exceptions thrown in them cannot be caught and will crash the application.
+
+## Code that triggers the analyzer
+
+```csharp
+public void SetupHandlers()
+{
+    // Dangerous: async void delegate
+    SomeEvent += async () =>
+    {
+        await SomeAsyncMethod();
+        // If this throws, it will crash the app
+    };
+
+    // Another dangerous pattern
+    Task.Run(async () =>
+    {
+        await ProcessAsync();
+        // Exceptions here are unhandled
+    });
+}
+```
+
+```csharp
+public void RegisterCallback()
+{
+    // Async void delegate in callback
+    RegisterCallback(async () =>
+    {
+        await DoWorkAsync();
+    });
+}
+```
+
+## How to fix
+
+Use regular void-return method and make a blocking call to async method.
+
+```csharp
+public void SetupHandlers()
+{
+    // Safe: async Task delegate
+    SomeEvent += (sender, e) =>
+    {
+        try
+        {
+            SomeAsyncMethod().GetAwaiter().GetResult();
+        }
+        catch (Exception ex)
+        {
+            // Handle exception properly
+            LogError(ex);
+        }
+    };}
+```