1 files changed, 39 insertions, 0 deletions
diff --git a/src/Cepis/CepisException.cs b/src/Cepis/CepisException.cs
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+++ b/src/Cepis/CepisException.cs
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+namespace Cepis;
+
+/// <summary>
+/// The base of every error this library raises. Catch it to handle any failure.
+/// </summary>
+/// <remarks>
+/// <para>
+/// Below this type the split is by <b>the decision the caller has to make</b>,
+/// not by the HTTP status that caused it.
+/// <see cref="InvalidCepException"/> and <see cref="CepNotFoundException"/> are
+/// problems with the <i>request</i>: retrying is pointless, the same CEP will
+/// fail again. <see cref="NetworkException"/>, <see cref="ServerErrorException"/>
+/// and <see cref="RateLimitedException"/> are problems with <i>transport</i>:
+/// retrying may help, and the client already retried on its own before throwing
+/// any of them.
+/// </para>
+/// <para>
+/// C# allows one base class, so these are not also <see cref="ArgumentException"/>
+/// or <see cref="KeyNotFoundException"/>: one base type that catches every
+/// failure is worth more.
+/// </para>
+/// </remarks>
+public abstract class CepisException : Exception
+{
+    /// <summary>Create the exception with a message.</summary>
+    /// <param name="message">what went wrong</param>
+    protected CepisException(string message)
+        : base(message)
+    {
+    }
+
+    /// <summary>Create the exception with a message and an underlying cause.</summary>
+    /// <param name="message">what went wrong</param>
+    /// <param name="innerException">the failure underneath, if any</param>
+    protected CepisException(string message, Exception? innerException)
+        : base(message, innerException)
+    {
+    }
+}