Merge pull request 293 from dev/write-error into develop

Merge dev/write-error to develop

src/pester-tests/Write-Error.Tests.ps1

@@ -0,0 +1,35 @@
+Describe "Write-Error" {
+    It "Should be able to throw" {
+        Write-Error "test throw" -ErrorAction SilentlyContinue | Should Throw
+    }
+
+    It "Should throw a non-terminating error" {
+        Write-Error "test throw" -ErrorAction SilentlyContinue
+
+        1 + 1 | Should Be 2
+    }
+
+    It "Should trip an exception using the exception switch" {
+        $var = 0
+        try
+        {
+            Write-Error -Exception -Message "test throw"
+        }
+        catch [System.Exception]
+        {
+            
+            $var++
+        }
+        finally
+        {
+            $var | Should Be 1
+        }
+    }
+
+    It "Should output the error message to the `$error automatic variable" {
+        $theError = "Error: Too many input values."
+        write-error -message $theError -category InvalidArgument -ErrorAction SilentlyContinue
+
+        $error[0]| Should Be $theError
+    }
+}