report errors when running rebar --version (aids #488)

Author: deadok22

src/org/intellij/erlang/rebar/settings/RebarConfigurationForm.java

@@ -22,6 +22,7 @@
 import com.intellij.openapi.ui.TextFieldWithBrowseButton;
 import com.intellij.openapi.util.Pair;
 import com.intellij.openapi.util.io.FileUtilRt;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.ui.DocumentAdapter;
 import com.intellij.ui.components.labels.ActionLink;
@@ -82,14 +83,17 @@ public JComponent createComponent() {
 
   private boolean validateRebarPath() {
     String rebarPath = myRebarPathSelector.getText();
-    if (new File(rebarPath).exists()) {
-      String version = ExtProcessUtil.restrictedTimeExec(myRebarPathSelector.getText() + " --version", 3000);
-      if (version.startsWith("rebar")) {
-        myRebarVersionText.setText(version);
-        return true;
-      }
+    if (!new File(rebarPath).exists()) return false;
+
+    ExtProcessUtil.ExtProcessOutput output = ExtProcessUtil.execAndGetFirstLine(myRebarPathSelector.getText() + " --version", 3000);
+    String version = output.getStdOut();
+    if (version.startsWith("rebar")) {
+      myRebarVersionText.setText(version);
+      return true;
     }
-    myRebarVersionText.setText("N/A");
+
+    String stdErr = output.getStdErr();
+    myRebarVersionText.setText("N/A" + (StringUtil.isNotEmpty(stdErr) ? ": Error: " + stdErr : ""));
     return false;
   }
 

src/org/intellij/erlang/settings/ErlangExternalToolsConfigurable.java

@@ -27,7 +27,6 @@
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.ui.TitledSeparator;
-import com.intellij.util.containers.ContainerUtil;
 import org.intellij.erlang.dialyzer.DialyzerSettings;
 import org.intellij.erlang.emacs.EmacsSettings;
 import org.intellij.erlang.rebar.settings.RebarConfigurationForm;
@@ -42,7 +41,6 @@
 
 import javax.swing.*;
 import java.io.File;
-import java.util.List;
 
 public class ErlangExternalToolsConfigurable implements SearchableConfigurable, Configurable.NoScroll {
   public static final String ERLANG_RELATED_TOOLS = "Erlang External Tools";
@@ -168,13 +166,7 @@ public void disposeUIResources() {
   }
 
   private void validateEmacsPath() {
-    String version = ExtProcessUtil.restrictedTimeExec(myEmacsPathSelector.getText() + " --version", 3000);
-    List<String> split = StringUtil.split(version, "\n");
-    if (StringUtil.containsIgnoreCase(version, "emacs") && split.size() > 0) {
-      myEmacsVersionText.setText(ContainerUtil.getFirstItem(split));
-    }
-    else {
-      myEmacsVersionText.setText("N/A");
-    }
+    String rawVersion = ExtProcessUtil.execAndGetFirstLine(myEmacsPathSelector.getText() + " --version", 3000).getStdOut();
+    myEmacsVersionText.setText(StringUtil.containsIgnoreCase(rawVersion, "emacs") ? rawVersion : "N/A");
   }
 }

src/org/intellij/erlang/utils/ExtProcessUtil.java

@@ -16,10 +16,12 @@
 
 package org.intellij.erlang.utils;
 
+import com.intellij.openapi.util.text.StringUtil;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.concurrent.*;
 
@@ -28,21 +30,17 @@ private ExtProcessUtil() {
   }
 
   @NotNull
-  public static String restrictedTimeExec(@NotNull String cmd, int timeout) {
+  public static ExtProcessOutput execAndGetFirstLine(@NotNull String cmd, long timeout) {
     try {
       final Process cmdRunner = Runtime.getRuntime().exec(cmd);
       ExecutorService singleTreadExecutor = Executors.newSingleThreadExecutor();
-      Future<String> cmdRunnerFuture = singleTreadExecutor.submit(new Callable<String>() {
+      Future<ExtProcessOutput> cmdRunnerFuture = singleTreadExecutor.submit(new Callable<ExtProcessOutput>() {
         @Override
-        public String call() throws Exception {
+        public ExtProcessOutput call() throws Exception {
           cmdRunner.waitFor();
-          BufferedReader outReader = new BufferedReader(new InputStreamReader(cmdRunner.getInputStream()));
-          try {
-            String firstLine = outReader.readLine();
-            return firstLine == null ? "" : firstLine;
-          } finally {
-            outReader.close();
-          }
+          String stdOut = readLine(cmdRunner.getInputStream());
+          String stdErr = readLine(cmdRunner.getErrorStream());
+          return new ExtProcessOutput(stdOut, stdErr);
         }
       });
       try {
@@ -53,6 +51,41 @@ public String call() throws Exception {
       singleTreadExecutor.shutdown();
     } catch (IOException e) { // Suppress
     }
+    return new ExtProcessOutput("", "");
+  }
+
+  @NotNull
+  private static String readLine(InputStream stream) {
+    BufferedReader errReader = new BufferedReader(new InputStreamReader(stream));
+    try {
+      return StringUtil.notNullize(errReader.readLine());
+    } catch (IOException ignore) {
+    } finally {
+      try {
+        errReader.close();
+      } catch (IOException ignore) {
+      }
+    }
     return "";
   }
+
+  public static class ExtProcessOutput {
+    private final String myStdOut;
+    private final String myStdErr;
+
+    public ExtProcessOutput(@NotNull String stdOut, @NotNull String stdErr) {
+      myStdOut = stdOut;
+      myStdErr = stdErr;
+    }
+
+    @NotNull
+    public String getStdOut() {
+      return myStdOut;
+    }
+
+    @NotNull
+    public String getStdErr() {
+      return myStdErr;
+    }
+  }
 }