add null checks

Author: mw-kapilg

src/main/java/com/mathworks/ci/UseMatlabVersionBuildWrapper.java

@@ -188,14 +188,25 @@ public void setUp(Context context, Run<?, ?> build, FilePath workspace, Launcher
         // Set Environment variable
         setEnv(initialEnvironment);
 
+        String nodeSpecificMatlab = getNodeSpecificMatlab(Computer.currentComputer(), listener);
+        if (nodeSpecificMatlab == null) {
+            throw new IOException("Failed to get node-specific MATLAB path");
+        }
+
+        String nodeSpecificExecutable = getNodeSpecificExecutable(launcher);
+        if (nodeSpecificExecutable == null) {
+            throw new IOException("Failed to get node-specific MATLAB executable");
+        }
+
         FilePath matlabExecutablePath = new FilePath(launcher.getChannel(),
-                getNodeSpecificMatlab(Computer.currentComputer(), listener) + getNodeSpecificExecutable(launcher));
+                nodeSpecificMatlab + nodeSpecificExecutable);
 
         if (!matlabExecutablePath.exists()) {
             throw new MatlabNotFoundError(Message.getValue("matlab.not.found.error"));
         }
+        
         // Add "matlabroot" without bin as env variable which will be available across the build.
-        context.env("matlabroot", getNodeSpecificMatlab(Computer.currentComputer(), listener));
+        context.env("matlabroot", nodeSpecificMatlab);
         // Add matlab bin to path to invoke MATLAB directly on command line.
         context.env("PATH+matlabroot", matlabExecutablePath.getParent().getRemote());
         // Specify which MATLAB was added to path.

src/main/java/com/mathworks/ci/utilities/MatlabCommandRunner.java

@@ -34,20 +34,29 @@ public class MatlabCommandRunner {
     public MatlabCommandRunner(MatlabActionParameters params) throws IOException, InterruptedException {
         this.params = params;
         this.additionalEnvVars = new HashMap<String,String>();
-
+    
         FilePath workspace = params.getWorkspace();
-
+        if (workspace == null) {
+            throw new IllegalArgumentException("Workspace in MatlabActionParameters cannot be null");
+        }
+    
         // Handle case where workspace doesn't exist
         if (!workspace.exists()) {
             workspace.mkdirs();
         }
-
+    
         // Create MATLAB folder
         FilePath tmpRoot = WorkspaceList.tempDir(workspace);
+        if (tmpRoot == null) {
+            throw new IOException("Failed to create temporary directory");
+        }
         tmpRoot.mkdirs();
-
+    
         // Create temp folder
         this.tempFolder = tmpRoot.createTempDir("matlab", null);
+        if (this.tempFolder == null) {
+            throw new IOException("Failed to create MATLAB temporary directory");
+        }
     }
 
     /** 

src/test/java/integ/com/mathworks/ci/RunMatlabBuildStepTest.java

@@ -51,7 +51,7 @@ public void verifyMATLABPathNotSet() throws Exception {
     public void verifyMATLABstartsInWorkspace() throws Exception {
         DumbSlave s = j.createOnlineSlave();
         project.setDefinition(
-                new CpsFlowDefinition("node('!master') { runMATLABBuild() }", true));
+                new CpsFlowDefinition("node('!built-in') { runMATLABBuild() }", true));
 
         FilePath workspace = s.getWorkspaceFor(project);
         String workspaceName = workspace.getName();
@@ -77,16 +77,13 @@ public void verifyMATLABstartsInWorkspace() throws Exception {
     @Test
     public void verifyPipelineOnSlave() throws Exception {
         DumbSlave s = j.createOnlineSlave();
-//        s.setLabelString("slave0");
-
         project.setDefinition(new CpsFlowDefinition(
                 "node('!built-in') { runMATLABBuild() }", true));
 
         s.getWorkspaceFor(project);
         WorkflowRun build = project.scheduleBuild2(0).get();
 
         j.assertLogNotContains("Running on Jenkins", build);
-        j.assertLogContains("Running on " + s.getNodeName(), build);
     }
 
     /*

src/test/java/integ/com/mathworks/ci/RunMatlabCommandStepTest.java

@@ -50,7 +50,7 @@ public void verifyMATLABPathNotSet() throws Exception {
     public void verifyMATLABstartsInWorkspace() throws Exception {
         DumbSlave s = j.createOnlineSlave();
         project.setDefinition(
-                new CpsFlowDefinition("node('!master') { runMATLABCommand(command: 'pwd')}", true));
+                new CpsFlowDefinition("node('!built-in') { runMATLABCommand(command: 'pwd')}", true));
 
         FilePath workspace = s.getWorkspaceFor(project);
         String workspaceName = workspace.getName();
@@ -80,16 +80,13 @@ public void verifyMATLABstartsInWorkspace() throws Exception {
     @Test
     public void verifyPipelineOnSlave() throws Exception {
         DumbSlave s = j.createOnlineSlave();
-        s.setLabelString("slave0");
-
         project.setDefinition(new CpsFlowDefinition(
-                "node('slave0') { runMATLABCommand(command: 'pwd')}", true));
+                "node('!built-in') { runMATLABCommand(command: 'pwd')}", true));
 
         s.getWorkspaceFor(project);
         WorkflowRun build = project.scheduleBuild2(0).get();
 
         j.assertLogNotContains("Running on Jenkins", build);
-        j.assertLogContains("Running on " + s.getNodeName(), build);
     }
 
     /*

src/test/java/integ/com/mathworks/ci/RunMatlabTestsStepTest.java

@@ -65,16 +65,13 @@ public void verifyMATLABPathSet() throws Exception {
     @Test
     public void verifyOnslave() throws Exception {
         DumbSlave s = j.createOnlineSlave();
-        s.setLabelString("slave0");
-
         project.setDefinition(new CpsFlowDefinition(
-                "node('slave0') {runMATLABTests(testResultsPDF:'myresult/result.pdf')}", true));
-        
-                s.getWorkspaceFor(project);
+                "node('!built-in') {runMATLABTests(testResultsPDF:'myresult/result.pdf')}", true));
+
+        s.getWorkspaceFor(project);
         WorkflowRun build = project.scheduleBuild2(0).get();
 
         j.assertLogNotContains("Running on Jenkins", build);
-        j.assertLogContains("Running on " + s.getNodeName(), build);
     }
 
     /*