Add tests from other infrastructure + enforce structure (#411)

Some of the tests here were contributed by @liupengy19 in another repo
that uses infrastructure based on SquinToStim. While they were
originally "higher up" in the pipeline the root cause of the problems
was in SquinToStim (as opposed to that other infrastructure).

Therefore I thought it better to move the tests here, closer to what
actually caused them to fail in the first place. I've also opted to put
the tests in their proper locations, as opposed to just have one file
for them from @kaihsin 's original structure (understandably faster but
makes it more confusing as to why the test is where it is).

---------

Co-authored-by: Kai-Hsin Wu <[email protected]>

Author: johnzl-777

test/stim/passes/stim_reference_programs/noise/apply_loss.stim

@@ -0,0 +1,3 @@
+I_ERROR[loss](0.10000000) 0
+I_ERROR[loss](0.10000000) 1
+I_ERROR[loss](0.10000000) 2

test/stim/passes/stim_reference_programs/qubit/addition_assignment_measure.stim

@@ -0,0 +1,2 @@
+MZ(0.00000000) 0
+MZ(0.00000000) 1

test/stim/passes/test_squin_meas_to_stim.py

@@ -5,6 +5,7 @@
 from bloqade import squin
 from bloqade.squin import op, qubit
 from bloqade.stim.emit import EmitStimMain
+from bloqade.squin.qubit import MeasurementResult
 from bloqade.stim.passes import SquinToStimPass
 
 
@@ -13,7 +14,16 @@ def codegen(mt: ir.Method):
     emit = EmitStimMain()
     emit.initialize()
     emit.run(mt=mt, args=())
-    return emit.get_output()
+    return emit.get_output().strip()
+
+
+def load_reference_program(filename):
+    """Load stim file."""
+    path = os.path.join(
+        os.path.dirname(__file__), "stim_reference_programs", "qubit", filename
+    )
+    with open(path, "r") as f:
+        return f.read().strip()
 
 
 def test_cond_on_measurement():
@@ -38,12 +48,21 @@ def main():
 
     SquinToStimPass(main.dialects)(main)
 
-    main.print()
 
-    path = os.path.join(
-        os.path.dirname(__file__), "stim_reference_programs", "simple_if_rewrite.txt"
-    )
-    with open(path, "r") as f:
-        base_stim_prog = f.read()
+def test_addition_assignment_on_measures_in_list():
+
+    @squin.kernel(fold=False)
+    def main():
+        q = qubit.new(2)
+        results = []
+
+        result: MeasurementResult = qubit.measure(q[0])
+        results += [result]
+        result: MeasurementResult = qubit.measure(q[1])
+        results += [result]
+
+    SquinToStimPass(main.dialects)(main)
+
+    base_stim_prog = load_reference_program("addition_assignment_measure.stim")
 
-    assert base_stim_prog.rstrip() == codegen(main)
+    assert base_stim_prog == codegen(main)

test/stim/passes/test_squin_noise_to_stim.py

@@ -3,14 +3,16 @@
 from kirin import ir
 
 from bloqade.squin import op, noise, qubit, kernel
+from bloqade.stim.emit import EmitStimMain
 from bloqade.stim.passes import SquinToStimPass
 
-from .test_squin_qubit_to_stim import codegen as _codegen
 
-
-def codegen(mt: ir.Method) -> str:
-    """Generate stim code."""
-    return _codegen(mt).strip()
+def codegen(mt: ir.Method):
+    # method should not have any arguments!
+    emit = EmitStimMain()
+    emit.initialize()
+    emit.run(mt=mt, args=())
+    return emit.get_output().strip()
 
 
 def load_reference_program(filename):
@@ -240,3 +242,19 @@ def test():
     SquinToStimPass(test.dialects)(test)
     expected_stim_program = load_reference_program("broadcast_iid_y_flip_channel.stim")
     assert codegen(test) == expected_stim_program
+
+
+def test_apply_loss():
+
+    @kernel
+    def test():
+        q = qubit.new(3)
+        loss = noise.qubit_loss(0.1)
+        qubit.apply(loss, q[0])
+        qubit.apply(loss, q[1])
+        qubit.apply(loss, q[2])
+
+    SquinToStimPass(test.dialects)(test)
+
+    expected_stim_program = load_reference_program("apply_loss.stim")
+    assert codegen(test) == expected_stim_program