Use dmypy instead of mypy

src/main/java/com/leinardi/pycharm/mypy/MypyConfigService.java

@@ -31,11 +31,13 @@ public class MypyConfigService implements PersistentStateComponent<MypyConfigSer
     private String mypyConfigFilePath;
     private String mypyArguments;
     private boolean scanBeforeCheckin;
+    private boolean useDaemon;
 
     public MypyConfigService() {
         customMypyPath = "";
         mypyArguments = "";
         mypyConfigFilePath = "";
+        useDaemon = false;
     }
 
     public String getCustomMypyPath() {
@@ -70,6 +72,14 @@ public void setScanBeforeCheckin(boolean scanBeforeCheckin) {
         this.scanBeforeCheckin = scanBeforeCheckin;
     }
 
+    public boolean isUseDaemon() {
+        return useDaemon;
+    }
+
+    public void setUseDaemon(boolean useDaemon) {
+        this.useDaemon = useDaemon;
+    }
+
     @Nullable
     @Override
     public MypyConfigService getState() {

src/main/java/com/leinardi/pycharm/mypy/MypyConfigurable.java

@@ -68,7 +68,8 @@ public void reset() {
     public boolean isModified() {
         boolean result = !configPanel.getMypyPath().equals(mypyConfigService.getCustomMypyPath())
                 || !configPanel.getMypyConfigFilePath().equals(mypyConfigService.getMypyConfigFilePath())
-                || !configPanel.getMypyArguments().equals(mypyConfigService.getMypyArguments());
+                || !configPanel.getMypyArguments().equals(mypyConfigService.getMypyArguments())
+                || !configPanel.getUseDaemon() == (mypyConfigService.isUseDaemon());
         if (LOG.isDebugEnabled()) {
             LOG.debug("Has config changed? " + result);
         }
@@ -80,6 +81,7 @@ public void apply() {
         mypyConfigService.setCustomMypyPath(configPanel.getMypyPath());
         mypyConfigService.setMypyConfigFilePath(configPanel.getMypyConfigFilePath());
         mypyConfigService.setMypyArguments(configPanel.getMypyArguments());
+        mypyConfigService.setUseDaemon(configPanel.getUseDaemon());
     }
 
     @Override

src/main/java/com/leinardi/pycharm/mypy/checker/ScannableFile.java

@@ -190,7 +190,7 @@ private File relativePathToModuleContentRoots(final @NotNull PsiFile file, final
     }
 
     private File prepareBaseTmpDirFor(final PsiFile tempPsiFile) {
-        final File baseTmpDir = new File(new TempDirProvider().forPersistedPsiFile(tempPsiFile),
+        final File baseTmpDir = new File(new TempDirProvider(tempPsiFile.getProject()).forPersistedPsiFile(tempPsiFile),
                 tempFileDirectoryName());
         baseTmpDir.deleteOnExit();
         return baseTmpDir;

src/main/java/com/leinardi/pycharm/mypy/mpapi/MypyRunner.java

@@ -46,7 +46,8 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.InterruptedIOException;
-import java.nio.charset.Charset;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -87,12 +88,9 @@ public static boolean isMypyPathValid(String mypyPath, Project project) {
             return false;
         }
         GeneralCommandLine cmd = getMypyCommandLine(project, mypyPath);
-        boolean daemon = false;
-        if (daemon) {
-            cmd.addParameter("status");
-        } else {
-            cmd.addParameter("-V");
-        }
+
+        cmd.addParameter("-V");
+
         final Process process;
         try {
             process = cmd.createProcess();
@@ -272,19 +270,23 @@ private static List<Issue> runMypy(Project project, Set<String> filesToScan, Str
         if (filesToScan.isEmpty()) {
             return Collections.emptyList();
         }
-        boolean daemon = false;
+
+        if (mypyConfigService.isUseDaemon()) {
+            // build path to dmypy by assuming that it sits right next to the selected mypy executable
+            // with the only difference being that the name has "dmypy" in it rather than just "mypy"
+            Path p = Paths.get(mypyPath);
+            String dFile = p.getFileName().toString().replace("mypy", "dmypy");
+            mypyPath = Paths.get(p.getParent().toString(), dFile).toString();
+        }
 
         GeneralCommandLine cmd = new GeneralCommandLine(mypyPath);
-        cmd.setCharset(Charset.forName("UTF-8"));
-        if (daemon) {
+        cmd.setCharset(UTF_8);
+        if (mypyConfigService.isUseDaemon()) {
             cmd.addParameter("run");
             cmd.addParameter("--");
-            cmd.addParameter("``--show-column-numbers");
-        } else {
-            cmd.addParameter("--show-column-numbers");
         }
-        cmd.addParameter("--follow-imports");
-        cmd.addParameter("silent");
+
+        cmd.addParameter("--show-column-numbers");
 
         injectEnvironmentVariables(project, cmd);
 
@@ -300,12 +302,31 @@ private static List<Issue> runMypy(Project project, Set<String> filesToScan, Str
             cmd.addParameter(file);
         }
         cmd.setWorkDirectory(project.getBasePath());
-        final Process process;
+
+        LOG.debug("Command Line string: " + cmd.getCommandLineString());
         try {
-            process = cmd.createProcess();
-            InputStream inputStream = process.getInputStream();
-            //TODO check stderr for errors
-            //            process.waitFor();
+            final int retryLimit = 5;
+            InputStream inputStream = null;
+            for (int retryCount = 1; retryCount <= retryLimit; retryCount++) {
+                final Process process = cmd.createProcess();
+                inputStream = process.getInputStream();
+
+                String error = new BufferedReader(new InputStreamReader(process.getErrorStream(), UTF_8))
+                        .lines().collect(Collectors.joining("\n"));
+                if (StringUtil.isEmpty(error)) {
+                    break;
+                } else {
+                    LOG.info("Command Line string: " + cmd.getCommandLineString());
+                    // the daemon sometimes fails when idea invokes the inspection multiple times
+                    if (mypyConfigService.isUseDaemon() && error.equals("The connection is busy.")) {
+                        LOG.warn(error + " attempt #" + retryCount);
+                    } else {
+                        throw new MypyToolException("Error while running Mypy: " + error);
+                    }
+                }
+            }
+
+            //  process.waitFor();
             return parseMypyOutput(inputStream);
         } catch (InterruptedIOException e) {
             LOG.info("Command Line string: " + cmd.getCommandLineString());

src/main/java/com/leinardi/pycharm/mypy/ui/MypyConfigPanel.form

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <form xmlns="http://www.intellij.com/uidesigner/form/" version="1" bind-to-class="com.leinardi.pycharm.mypy.ui.MypyConfigPanel">
-  <grid id="27dc6" binding="rootPanel" layout-manager="GridLayoutManager" row-count="4" column-count="3" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
+  <grid id="27dc6" binding="rootPanel" layout-manager="GridLayoutManager" row-count="5" column-count="3" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
     <margin top="0" left="0" bottom="0" right="0"/>
     <constraints>
       <xy x="20" y="20" width="667" height="184"/>
@@ -37,7 +37,7 @@
       </component>
       <vspacer id="1b350">
         <constraints>
-          <grid row="3" column="0" row-span="1" col-span="1" vsize-policy="6" hsize-policy="1" anchor="0" fill="2" indent="0" use-parent-layout="false"/>
+          <grid row="4" column="0" row-span="1" col-span="1" vsize-policy="6" hsize-policy="1" anchor="0" fill="2" indent="0" use-parent-layout="false"/>
         </constraints>
       </vspacer>
       <component id="90410" class="com.intellij.ui.components.JBLabel">
@@ -70,6 +70,14 @@
         </constraints>
         <properties/>
       </component>
+      <component id="14b64" class="com.intellij.ui.components.JBCheckBox" binding="useDaemonCheckBox">
+        <constraints>
+          <grid row="3" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="3" anchor="8" fill="0" indent="0" use-parent-layout="false"/>
+        </constraints>
+        <properties>
+          <text value="Use Daemon"/>
+        </properties>
+      </component>
     </children>
   </grid>
 </form>

src/main/java/com/leinardi/pycharm/mypy/ui/MypyConfigPanel.java

@@ -20,6 +20,7 @@
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.TextComponentAccessor;
 import com.intellij.openapi.ui.TextFieldWithBrowseButton;
+import com.intellij.ui.components.JBCheckBox;
 import com.intellij.ui.components.JBTextField;
 import com.leinardi.pycharm.mypy.MypyBundle;
 import com.leinardi.pycharm.mypy.MypyConfigService;
@@ -39,6 +40,7 @@ public class MypyConfigPanel {
     private com.intellij.openapi.ui.TextFieldWithBrowseButton mypyPathField;
     private com.intellij.openapi.ui.TextFieldWithBrowseButton mypyConfigFilePathField;
     private JBTextField argumentsField;
+    private JBCheckBox useDaemonCheckBox;
     private Project project;
 
     public MypyConfigPanel(Project project) {
@@ -66,6 +68,7 @@ public MypyConfigPanel(Project project) {
                 TextComponentAccessor.TEXT_FIELD_WHOLE_TEXT);
         argumentsField.setText(mypyConfigService.getMypyArguments());
         argumentsField.getEmptyText().setText(MypyBundle.message("config.optional"));
+        useDaemonCheckBox.setSelected(mypyConfigService.isUseDaemon());
     }
 
     public JPanel getPanel() {
@@ -92,6 +95,8 @@ public String getMypyArguments() {
         return argumentsField.getText();
     }
 
+    public boolean getUseDaemon() { return useDaemonCheckBox.isSelected(); }
+
     private void createUIComponents() {
         JBTextField autodetectTextField = new JBTextField();
         autodetectTextField.getEmptyText()

src/main/java/com/leinardi/pycharm/mypy/util/TempDirProvider.java

@@ -22,6 +22,7 @@
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiFile;
+import com.leinardi.pycharm.mypy.MypyConfigService;
 import org.jdesktop.swingx.util.OS;
 import org.jetbrains.annotations.NotNull;
 
@@ -34,9 +35,16 @@
  * Locate and/or create temporary directories for use by this plugin.
  */
 public class TempDirProvider {
+    public TempDirProvider(Project project) {
+        this.mypyConfigService = MypyConfigService.getInstance(project);
+    }
+
+    private final MypyConfigService mypyConfigService;
+
     public String forPersistedPsiFile(final PsiFile tempPsiFile) {
         String systemTempDir = System.getProperty("java.io.tmpdir");
-        if (OS.isWindows() && driveLetterOf(systemTempDir) != driveLetterOf(pathOf(tempPsiFile))) {
+        if (mypyConfigService.isUseDaemon() || (OS.isWindows() && driveLetterOf(systemTempDir) != driveLetterOf(pathOf(tempPsiFile)))) {
+            // for some reason the daemon reports no errors unless the file is in the project directory
             // Some tool on Windows requires the files to be on the same drive
             final File projectTempDir = temporaryDirectoryLocationFor(tempPsiFile.getProject());
             if (projectTempDir.exists() || projectTempDir.mkdirs()) {