Added example of task precondition and postcondition and another of T…

…askSetup and TearDown

Also reworded assert messages in two examples to show correct usage

examples/parameters.ps1

@@ -5,5 +5,5 @@
 task default -depends TestParams
 
 task TestParams { 
-	Assert ($my_property -ne $null) '$my_property should not be null'  
+	Assert ($my_property -ne $null) "`$my_property should not be null. Run with -parameters @{'p1' = 'v1'; 'p2' = 'v2'}"
 }

examples/preandpostcondition.ps1

@@ -0,0 +1,18 @@
+properties {
+  $runTaskA = $false
+  $taskBSucceded = $true
+}
+
+task default -depends TaskC
+
+task TaskA -precondition { $runTaskA -eq $true } {
+  "TaskA executed"
+}
+
+task TaskB -postcondition { $taskBSucceded -eq $true } {
+  "TaskB executed"
+}
+
+task TaskC -depends TaskA,TaskB {
+  "TaskC executed."
+}

examples/properties.ps1

@@ -1,13 +1,13 @@
 properties {
-	$x = $null
-	$y = $null
-	$z = $null
+  $x = $null
+  $y = $null
+  $z = $null
 }
 
 task default -depends TestProperties
 
 task TestProperties { 
-  Assert ($x -ne $null) "x should not be null"
-  Assert ($y -ne $null) "y should not be null"
+  Assert ($x -ne $null) "x should not be null. Run with -properties @{'x' = '1'; 'y' = '2'}"
+  Assert ($y -ne $null) "y should not be null. Run with -properties @{'x' = '1'; 'y' = '2'}"
   Assert ($z -eq $null) "z should be null"
 }

examples/tasksetupandteardown.ps1

@@ -0,0 +1,17 @@
+TaskSetup {
+  "Executing task setup"
+}
+
+TaskTearDown {
+  "Executing task tear down"
+}
+
+Task default -depends TaskB
+
+Task TaskA {
+  "TaskA executed"
+}
+
+Task TaskB -depends TaskA {
+  "TaskB executed"
+}