add documentation comments

add exceptions to readme

Author: Mark Kuhn

README.md

@@ -162,7 +162,7 @@ The `MetricsLogger` is the interface you will use to publish embedded metrics.
 
 Adds a new metric to the current logger context. Multiple metrics using the same key will be appended to an array of values. The Embedded Metric Format supports a maxumum of 100 metrics per key.
 
-Units must meet CloudWatch Metrics unit requirements, if not it will default to None. See [MetricDatum](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_MetricDatum.html) for valid values.
+Units must meet CloudWatch Metrics unit requirements, otherwise it will throw a `InvalidMetricException`. See [MetricDatum](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_MetricDatum.html) for valid values.
 
 Example:
 
@@ -196,7 +196,7 @@ Adds a new set of dimensions that will be associated with all metric values.
 If the cardinality of a particular value is expected to be high, you should consider
 using `setProperty` instead.
 
-Dimensions must meet CloudWatch Dimensions requirements. See [Dimensions](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_Dimension.html) for valid values.
+Dimensions must meet CloudWatch Dimensions requirements, otherwise it will throw a `InvalidDimensionException`. See [Dimensions](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_Dimension.html) for valid values.
 
 Example:
 
@@ -216,7 +216,7 @@ Explicitly override all dimensions. This will remove the default dimensions unle
 If the cardinality of a particular value is expected to be high, you should consider
 using `setProperty` instead.
 
-Dimensions must meet CloudWatch Dimensions requirements. See [Dimensions](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_Dimension.html) for valid values.
+Dimensions must meet CloudWatch Dimensions requirements, otherwise it will throw a `InvalidDimensionException`. See [Dimensions](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_Dimension.html) for valid values.
 
 Examples:
 
@@ -241,6 +241,7 @@ Explicitly clear all custom dimensions. Set `useDefault` to `true` to keep using
 - MetricsLogger **SetNamespace**(string logNamespace)
 
 Sets the CloudWatch [namespace](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_concepts.html#Namespace) that extracted metrics should be published to. If not set, a default value of aws-embedded-metrics will be used.
+Namespaces must meet CloudWatch Namespace requirements, otherwise it will throw a `InvalidNamespaceException`. See [Namespace](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_concepts.html#Namespace) for valid values.
 
 Example:
 

src/Amazon.CloudWatch.EMF/Utils/Validator.cs

@@ -5,6 +5,12 @@ namespace Amazon.CloudWatch.EMF.Utils
 {
     public class Validator
     {
+        /// <summary>
+        /// Validates dimension set.
+        /// </summary>
+        /// <param name="dimensionName">Dimension name</param>
+        /// <param name="dimensionValue">Dimension value</param>
+        /// <exception cref="InvalidDimensionException">Thrown when dimension name or value is invalid</exception>
         internal static void ValidateDimensionSet(in string dimensionName, in string dimensionValue)
         {
             if (dimensionName == null || dimensionName.Trim().Length == 0)
@@ -43,6 +49,12 @@ internal static void ValidateDimensionSet(in string dimensionName, in string dim
             }
         }
 
+        /// <summary>
+        /// Validates metric name.
+        /// </summary>
+        /// <param name="name">Metric name</param>
+        /// <param name="value">Metric value</param>
+        /// <exception cref="InvalidMetricException">Thrown when metric name or value is invalid</exception>
         internal static void ValidateMetric(in string name, in double value)
         {
             if (name == null || name.Trim().Length == 0)
@@ -61,6 +73,11 @@ internal static void ValidateMetric(in string name, in double value)
             }
         }
 
+        /// <summary>
+        /// Validates namespace.
+        /// </summary>
+        /// <param name="@namespace">Namespace</param>
+        /// <exception cref="InvalidNamespaceException">Thrown when namespace is invalid</exception>
         internal static void ValidateNamespace(in string @namespace)
         {
             if (@namespace == null || @namespace.Trim().Length == 0)
@@ -79,6 +96,11 @@ internal static void ValidateNamespace(in string @namespace)
             }
         }
 
+        /// <summary>
+        /// Checks if given string is only ASCII.
+        /// </summary>
+        /// <param name="str">String to check</param>
+        /// <returns>True if string is only ASCII, false otherwise</returns>
         private static bool IsAscii(in string str)
         {
             return Encoding.UTF8.GetByteCount(str) == str.Length;