processing
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
@@ -98,6 +98,7 @@ compose.desktop {
 dependencies {
     implementation(project(":core"))
     runtimeOnly(project(":java"))
+    implementation(project(":app:utils"))
 
     implementation(libs.flatlaf)
 

diff --git a/app/src/processing/app/Mode.java b/app/src/processing/app/Mode.java
@@ -40,6 +40,7 @@
 import processing.app.ui.Recent;
 import processing.app.ui.Toolkit;
 import processing.core.PApplet;
+import processing.utils.SketchException;
 
 
 public abstract class Mode {

diff --git a/app/src/processing/app/SketchException.java b/app/src/processing/app/SketchException.java
@@ -1,162 +1,30 @@
-/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
-
-/*
-  Part of the Processing project - http://processing.org
-
-  Copyright (c) 2004-08 Ben Fry and Casey Reas
-  Copyright (c) 2001-04 Massachusetts Institute of Technology
-
-  This program is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software Foundation,
-  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-*/
+// temporary band-aid class to support modes which are still looking here for the now-refactored class.
+//  - josh giesbrecht
 
 package processing.app;
 
+@Deprecated
+// please migrate to using processing.utils.SketchException instead! all class functionality is the same as before.
+public class SketchException extends processing.utils.SketchException {
 
-/**
- * An exception with a line number attached that occurs
- * during either pre-processing, compile, or run time.
- */
-public class SketchException extends Exception {
-  protected String message;
-  protected int codeIndex;
-  protected int codeLine;
-  protected int codeColumn;
-  protected boolean showStackTrace;
-
-
-  public SketchException(String message) {
-    this(message, true);
-  }
-
-
-  public SketchException(String message, boolean showStackTrace) {
-    this(message, -1, -1, -1, showStackTrace);
-  }
-
-
-  public SketchException(String message, int file, int line) {
-    this(message, file, line, -1, true);
-  }
-
-
-  public SketchException(String message, int file, int line, int column) {
-    this(message, file, line, column, true);
-  }
-
-
-  public SketchException(String message, int file, int line, int column,
-                         boolean showStackTrace) {
-    this.message = message;
-    this.codeIndex = file;
-    this.codeLine = line;
-    this.codeColumn = column;
-    this.showStackTrace = showStackTrace;
-  }
-
-
-  /**
-   * Override getMessage() in Throwable, so that I can set
-   * the message text outside the constructor.
-   */
-  public String getMessage() {
-    return message;
-  }
-
-
-  public void setMessage(String message) {
-    this.message = message;
-  }
-
-
-  public int getCodeIndex() {
-    return codeIndex;
-  }
-
-
-  public void setCodeIndex(int index) {
-    codeIndex = index;
-  }
-
-
-  public boolean hasCodeIndex() {
-    return codeIndex != -1;
-  }
-
-
-  public int getCodeLine() {
-    return codeLine;
-  }
-
-
-  public void setCodeLine(int line) {
-    this.codeLine = line;
-  }
-
-
-  public boolean hasCodeLine() {
-    return codeLine != -1;
-  }
-
-
-  public void setCodeColumn(int column) {
-    this.codeColumn = column;
-  }
-
-
-  public int getCodeColumn() {
-    return codeColumn;
-  }
-
-
-  public void showStackTrace() {
-    showStackTrace = true;
-  }
-
-
-  public void hideStackTrace() {
-    showStackTrace = false;
-  }
-
-
-  public boolean isStackTraceEnabled() {
-    return showStackTrace;
-  }
+    // Idea complained without all these super wrappers for constructors. ¯\_(ツ)_/¯ sure, why not?
+    public SketchException(String message) {
+        super(message);
+    }
 
+    public SketchException(String message, boolean showStackTrace) {
+        super(message, showStackTrace);
+    }
 
-  /**
-   * Nix the java.lang crap out of an exception message
-   * because it scares the children.
-   * <P>
-   * This function must be static to be used with super()
-   * in each of the constructors above.
-   */
-  /*
-  static public final String massage(String msg) {
-    if (msg.indexOf("java.lang.") == 0) {
-      //int dot = msg.lastIndexOf('.');
-      msg = msg.substring("java.lang.".length());
+    public SketchException(String message, int file, int line) {
+        super(message, file, line);
     }
-    return msg;
-    //return (dot == -1) ? msg : msg.substring(dot+1);
-  }
-  */
 
+    public SketchException(String message, int file, int line, int column) {
+        super(message, file, line, column);
+    }
 
-  public void printStackTrace() {
-    if (showStackTrace) {
-      super.printStackTrace();
+    public SketchException(String message, int file, int line, int column, boolean showStackTrace) {
+        super(message, file, line, column, showStackTrace);
     }
-  }
 }
diff --git a/app/src/processing/app/ui/Editor.java b/app/src/processing/app/ui/Editor.java
@@ -61,7 +61,7 @@
 import processing.app.RunnerListener;
 import processing.app.Sketch;
 import processing.app.SketchCode;
-import processing.app.SketchException;
+import processing.utils.SketchException;
 import processing.app.contrib.ContributionManager;
 import processing.app.laf.PdeMenuItemUI;
 import processing.app.syntax.*;

diff --git a/app/utils/build.gradle.kts b/app/utils/build.gradle.kts
@@ -0,0 +1,16 @@
+plugins {
+    id("java")
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation(platform("org.junit:junit-bom:5.10.0"))
+    testImplementation("org.junit.jupiter:junit-jupiter")
+}
+
+tasks.test {
+    useJUnitPlatform()
+}
diff --git a/app/utils/src/main/java/processing/utils/SketchException.java b/app/utils/src/main/java/processing/utils/SketchException.java
@@ -0,0 +1,162 @@
+/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
+
+/*
+  Part of the Processing project - http://processing.org
+
+  Copyright (c) 2004-08 Ben Fry and Casey Reas
+  Copyright (c) 2001-04 Massachusetts Institute of Technology
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software Foundation,
+  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+package processing.utils;
+
+
+/**
+ * An exception with a line number attached that occurs
+ * during either pre-processing, compile, or run time.
+ */
+public class SketchException extends Exception {
+    protected String message;
+    protected int codeIndex;
+    protected int codeLine;
+    protected int codeColumn;
+    protected boolean showStackTrace;
+
+
+    public SketchException(String message) {
+        this(message, true);
+    }
+
+
+    public SketchException(String message, boolean showStackTrace) {
+        this(message, -1, -1, -1, showStackTrace);
+    }
+
+
+    public SketchException(String message, int file, int line) {
+        this(message, file, line, -1, true);
+    }
+
+
+    public SketchException(String message, int file, int line, int column) {
+        this(message, file, line, column, true);
+    }
+
+
+    public SketchException(String message, int file, int line, int column,
+                           boolean showStackTrace) {
+        this.message = message;
+        this.codeIndex = file;
+        this.codeLine = line;
+        this.codeColumn = column;
+        this.showStackTrace = showStackTrace;
+    }
+
+
+    /**
+     * Override getMessage() in Throwable, so that I can set
+     * the message text outside the constructor.
+     */
+    public String getMessage() {
+        return message;
+    }
+
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+
+    public int getCodeIndex() {
+        return codeIndex;
+    }
+
+
+    public void setCodeIndex(int index) {
+        codeIndex = index;
+    }
+
+
+    public boolean hasCodeIndex() {
+        return codeIndex != -1;
+    }
+
+
+    public int getCodeLine() {
+        return codeLine;
+    }
+
+
+    public void setCodeLine(int line) {
+        this.codeLine = line;
+    }
+
+
+    public boolean hasCodeLine() {
+        return codeLine != -1;
+    }
+
+
+    public void setCodeColumn(int column) {
+        this.codeColumn = column;
+    }
+
+
+    public int getCodeColumn() {
+        return codeColumn;
+    }
+
+
+    public void showStackTrace() {
+        showStackTrace = true;
+    }
+
+
+    public void hideStackTrace() {
+        showStackTrace = false;
+    }
+
+
+    public boolean isStackTraceEnabled() {
+        return showStackTrace;
+    }
+
+
+    /**
+     * Nix the java.lang crap out of an exception message
+     * because it scares the children.
+     * <P>
+     * This function must be static to be used with super()
+     * in each of the constructors above.
+     */
+  /*
+  static public final String massage(String msg) {
+    if (msg.indexOf("java.lang.") == 0) {
+      //int dot = msg.lastIndexOf('.');
+      msg = msg.substring("java.lang.".length());
+    }
+    return msg;
+    //return (dot == -1) ? msg : msg.substring(dot+1);
+  }
+  */
+
+
+    public void printStackTrace() {
+        if (showStackTrace) {
+            super.printStackTrace();
+        }
+    }
+}
diff --git a/java/build.gradle.kts b/java/build.gradle.kts
@@ -26,6 +26,7 @@ dependencies{
     implementation(project(":app"))
     implementation(project(":core"))
     implementation(project(":java:preprocessor"))
+    implementation(project(":app:utils"))
 
     implementation(libs.eclipseJDT)
     implementation(libs.eclipseJDTCompiler)