fix default handling of script-file-path

Fixes the default handling of script-file-path property in
script trigger to more closely match the default behavior
when saving a job configuration in the Jenkins UI.

The previous behavior of setting script-file-path to an empty
string resulted in exceptions in the Jenkins log.

org.jenkinsci.plugins.scripttrigger.ScriptTriggerException:
The script file path '' doesn't exist.

Change-Id: I3d07892685c96824041efb102b2a474c22a2b9a7

jenkins_jobs/modules/triggers.py

@@ -1117,7 +1117,7 @@ def script(parser, xml_parent, data):
 
     :arg str label: Restrict where the polling should run. (default '')
     :arg str script: A shell or batch script. (default '')
-    :arg str script-file-path: A shell or batch script path. (default '')
+    :arg str script-file-path: A shell or batch script path. (optional)
     :arg str cron: cron syntax of when to run (default '')
     :arg bool enable-concurrent:  Enables triggering concurrent builds.
                                   (default false)
@@ -1136,8 +1136,9 @@ def script(parser, xml_parent, data):
     label = data.get('label')
 
     XML.SubElement(st, 'script').text = str(data.get('script', ''))
-    XML.SubElement(st, 'scriptFilePath').text = str(
-        data.get('script-file-path', ''))
+    if 'script-file-path' in data:
+        XML.SubElement(st, 'scriptFilePath').text = str(
+            data.get('script-file-path'))
     XML.SubElement(st, 'spec').text = str(data.get('cron', ''))
     XML.SubElement(st, 'labelRestriction').text = str(bool(label)).lower()
     if label:

tests/triggers/fixtures/script001.xml

@@ -3,7 +3,6 @@
   <triggers class="vector">
     <org.jenkinsci.plugins.scripttrigger.ScriptTrigger>
       <script>exit 0</script>
-      <scriptFilePath/>
       <spec>H/15 * * * *</spec>
       <labelRestriction>true</labelRestriction>
       <triggerLabel>master</triggerLabel>

tests/triggers/fixtures/script002.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project>
+  <triggers class="vector">
+    <org.jenkinsci.plugins.scripttrigger.ScriptTrigger>
+      <script>exit 0</script>
+      <scriptFilePath>$WORKSPACE/scripts</scriptFilePath>
+      <spec>H/15 * * * *</spec>
+      <labelRestriction>true</labelRestriction>
+      <triggerLabel>master</triggerLabel>
+      <enableConcurrentBuild>false</enableConcurrentBuild>
+      <exitCode>0</exitCode>
+    </org.jenkinsci.plugins.scripttrigger.ScriptTrigger>
+  </triggers>
+</project>

tests/triggers/fixtures/script002.yaml

@@ -0,0 +1,9 @@
+triggers:
+  - script:
+        script: 'exit 0'
+        script-file-path: '$WORKSPACE/scripts'
+        cron: 'H/15 * * * *'
+        enable-concurrent: False
+        label: master
+        exit-code: 0
+