Fix debugging for Flask server run configuration (PY-27926)

python/src/com/jetbrains/python/run/PythonCommandLineState.java

@@ -102,6 +102,7 @@ public abstract class PythonCommandLineState extends CommandLineState {
    */
   public static final String GROUP_MODULE = "Module";
   public static final String GROUP_SCRIPT = "Script";
+  public static final String MODULE_PARAMETER = "-m";
   private final AbstractPythonRunConfiguration myConfig;
 
   private Boolean myMultiprocessDebug = null;
@@ -269,9 +270,26 @@ public abstract class PythonCommandLineState extends CommandLineState {
     return new PyRemoteProcessStarter();
   }
 
+  /**
+   * Generate command line and apply patchers
+   *
+   * @param patchers array of patchers
+   * @return generated command line changed by patchers
+   */
+  @NotNull
+  public final GeneralCommandLine generateCommandLine(@Nullable CommandLinePatcher[] patchers) {
+    return applyPatchers(generateCommandLine(), patchers);
+  }
 
-  public GeneralCommandLine generateCommandLine(CommandLinePatcher[] patchers) {
-    GeneralCommandLine commandLine = generateCommandLine();
+  /**
+   * Apply patchers to the given command line
+   *
+   * @param commandLine command line to change
+   * @param patchers    array of patchers
+   * @return command line changed by patchers
+   */
+  @NotNull
+  private static GeneralCommandLine applyPatchers(@NotNull GeneralCommandLine commandLine, @Nullable CommandLinePatcher[] patchers) {
     if (patchers != null) {
       for (CommandLinePatcher patcher : patchers) {
         if (patcher != null) patcher.patchCommandLine(commandLine);
@@ -284,6 +302,14 @@ public abstract class PythonCommandLineState extends CommandLineState {
     return PythonProcessRunner.createProcess(commandLine);
   }
 
+  /**
+   * Generate command line from run configuration.
+   * It can be overridden if commandline shouldn't be based on the run configuration or when it requires some additional changes
+   * before patchers applying.
+   *
+   * @return generated command line
+   */
+  @NotNull
   public GeneralCommandLine generateCommandLine() {
     GeneralCommandLine commandLine = createPythonCommandLine(myConfig.getProject(), myConfig, isDebug(), myRunWithPty);
 

python/src/com/jetbrains/python/run/PythonScriptCommandLineState.java

@@ -230,7 +230,7 @@ public class PythonScriptCommandLineState extends PythonCommandLineState {
       ParamsGroup moduleParameters = parametersList.getParamsGroup(GROUP_MODULE);
       assert moduleParameters != null;
 
-      moduleParameters.addParameter("-m");
+      moduleParameters.addParameter(MODULE_PARAMETER);
       moduleParameters.addParameters(myConfig.getScriptName());
     }
     else {

python/src/com/jetbrains/python/testing/PyTestsShared.kt

@@ -234,8 +234,8 @@ abstract class PyTestExecutionEnvironment<T : PyAbstractTestConfiguration>(confi
 
   override fun getTestSpecs(): MutableList<String> = java.util.ArrayList(configuration.getTestSpec())
 
-  override fun generateCommandLine(patchers: Array<out CommandLinePatcher>?): GeneralCommandLine {
-    val line = super.generateCommandLine(patchers)
+  override fun generateCommandLine(): GeneralCommandLine {
+    val line = super.generateCommandLine()
     line.workDirectory = java.io.File(configuration.workingDirectorySafe)
     return line
   }

python/src/com/jetbrains/python/testing/PythonTestCommandLineStateBase.java

@@ -97,6 +97,7 @@ public abstract class PythonTestCommandLineStateBase<T extends AbstractPythonRun
     return null;  // by default, the IDE will use a "file://" protocol locator
   }
 
+  @NotNull
   @Override
   public GeneralCommandLine generateCommandLine() {
     GeneralCommandLine cmd = super.generateCommandLine();