diff --git a/tests/plugins/SpaceCadet/no-delay/no-delay.ino b/tests/plugins/SpaceCadet/no-delay/no-delay.ino
new file mode 100644
index 00000000..7881a202
--- /dev/null
+++ b/tests/plugins/SpaceCadet/no-delay/no-delay.ino
@@ -0,0 +1,68 @@
+/* -*- mode: c++ -*-
+ * Copyright (C) 2021 Keyboard.io, Inc.
+ *
+ * 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, version 3.
+ *
+ * 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, see .
+ */
+
+#include
+#include
+
+// *INDENT-OFF*
+KEYMAPS(
+ [0] = KEYMAP_STACKED
+ (
+ Key_LeftShift, Key_RightShift, ___, ___, ___, ___, ___,
+ Key_A, Key_B, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___,
+ ___,
+
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___,
+ ___
+ ),
+)
+// *INDENT-ON*
+
+KALEIDOSCOPE_INIT_PLUGINS(SpaceCadet);
+
+void setup() {
+ Kaleidoscope.setup();
+
+ //Set the SpaceCadet map
+ //Setting is {KeyThatWasPressed, AlternativeKeyToSend, TimeoutInMS}
+ //Note: must end with the SPACECADET_MAP_END delimiter
+ static kaleidoscope::plugin::SpaceCadet::KeyBinding spacecadetmap[] = {
+ {Key_LeftShift, Key_X, 10},
+ {Key_RightShift, Key_Y, 0},
+ {Key_LeftGui, Key_LeftCurlyBracket, 10},
+ {Key_RightAlt, Key_RightCurlyBracket, 10},
+ {Key_LeftAlt, Key_RightCurlyBracket, 10},
+ {Key_LeftControl, Key_LeftBracket, 10},
+ {Key_RightControl, Key_RightBracket, 10},
+ SPACECADET_MAP_END
+ };
+ //Set the map.
+ SpaceCadet.map = spacecadetmap;
+ SpaceCadet.time_out = 20;
+
+ SpaceCadet.enableWithoutDelay();
+}
+
+void loop() {
+ Kaleidoscope.loop();
+}
diff --git a/tests/plugins/SpaceCadet/no-delay/sketch.json b/tests/plugins/SpaceCadet/no-delay/sketch.json
new file mode 100644
index 00000000..8cc86922
--- /dev/null
+++ b/tests/plugins/SpaceCadet/no-delay/sketch.json
@@ -0,0 +1,6 @@
+{
+ "cpu": {
+ "fqbn": "keyboardio:virtual:model01",
+ "port": ""
+ }
+}
diff --git a/tests/plugins/SpaceCadet/no-delay/test.ktest b/tests/plugins/SpaceCadet/no-delay/test.ktest
new file mode 100644
index 00000000..ba35c59a
--- /dev/null
+++ b/tests/plugins/SpaceCadet/no-delay/test.ktest
@@ -0,0 +1,141 @@
+VERSION 1
+
+KEYSWITCH LSHIFT 0 0
+KEYSWITCH RSHIFT 0 1
+KEYSWITCH A 1 0
+KEYSWITCH B 1 1
+
+# ==============================================================================
+NAME SpaceCadet tap
+
+RUN 4 ms
+PRESS LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift # Report should contain `shift` (0xE1)
+
+RUN 4 ms
+RELEASE LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # Report should be empty
+EXPECT keyboard-report Key_X # Report should contain `X` (0x1B)
+EXPECT keyboard-report empty # Report should be empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME SpaceCadet hold
+
+RUN 4 ms
+PRESS LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift # Report should contain `shift` (0xE1)
+
+RUN 10 ms # timeout = 10 ms (for this key)
+RELEASE LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # Report should be empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME SpaceCadet hold with global timeout
+
+RUN 4 ms
+PRESS RSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_RightShift # Report should contain `shift` (0xE5)
+
+RUN 20 ms # timeout = 20 ms
+RELEASE RSHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # Report should be empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME SpaceCadet interrupt
+
+RUN 4 ms
+PRESS LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift # Report should contain `shift` (0xE1)
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift Key_A # Report should add `A` (0x04, 0xE1)
+
+RUN 4 ms
+RELEASE LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_A # Report should contain only `A` (0x04)
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty # Report should be empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME SpaceCadet interrupt SpaceCadet with tap
+
+RUN 4 ms
+PRESS LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift # Report should contain `shift` (0xE1)
+
+RUN 4 ms
+PRESS RSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift Key_RightShift # Report should add `shift` (0xE5)
+
+RUN 4 ms
+RELEASE RSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift # Report should contain `shift` (0xE1)
+EXPECT keyboard-report Key_LeftShift Key_Y # Report should add `Y` (0x1C)
+EXPECT keyboard-report Key_LeftShift # Report should contain `shift` (0xE1)
+
+RUN 4 ms
+RELEASE LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # Report should be empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME SpaceCadet interrupt SpaceCadet with hold
+
+# First, press left shift. It takes effect immediately, because SpaceCadet is in
+# "no-delay" mode.
+RUN 4 ms
+PRESS LSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift # report: { e1 }
+
+# Before left shift times out (timeout=10ms), press right shift, which also
+# takes effect without delay.
+RUN 4 ms
+PRESS RSHIFT
+RUN 1 cycle
+EXPECT keyboard-report Key_LeftShift Key_RightShift # report: { e1 e5 }
+
+# Next, release left shift after it times out (so it's not a "tap"), but before
+# the right shift times out. This does not generate a report, because the right
+# shift might still become a "tap" if it's released soon enough.
+RUN 10 ms
+RELEASE LSHIFT
+
+# Next, the right shift times out, resolving to its modifier state. This allows
+# the left shift to be released, because the right shift can't be a "tap".
+RUN 10 ms
+EXPECT keyboard-report Key_RightShift # Report should contain `shift` (0xE5)
+
+# Last, release the right shift as normal.
+RUN 4 ms
+RELEASE RSHIFT
+RUN 1 cycle
+EXPECT keyboard-report empty # Report should be empty
+
+RUN 5 ms