added SLEEP tests and support for python expressions in the SLEEP sta…

…tement

shepherd/Tester.py

@@ -374,10 +374,10 @@ def sleep_function(expression):
     if expression == '':
         raise Exception('expected a time afer after SLEEP')
     try:
-        amount = float(expression)
+        amount = float(evaluate_python(expression))
     except ValueError as e:
         raise Exception(f'expected a time afer after SLEEP, but got {expression}')
-    time.Sleep(amount)
+    time.sleep(amount)
 
 def read_function(line):
     """

shepherd/tests/TESTING_DOCS.md

@@ -62,9 +62,9 @@ Usage: `PRINTP <python expression>`
 
 The SLEEP statement is used in order to pause the execution of the .shepherd interpreter for a specified amount of time. Any LCM messages received
 while the interpreter is paused will still be recorded and may be processed by the next WAIT statement that the interpreter encounters. The sleep
-time may be a decimal, and is in terms of seconds.
+time may be a decimal, and is in terms of seconds. SLEEP may take a python expression as an argument, so long as it evaluates to a float.
 
-Usage: `SLEEP <time>`
+Usage: `SLEEP <time / python expression>`
 
 ### IF
 

shepherd/tests/testing_tests/sleep_test.shepherd

@@ -0,0 +1,25 @@
+## small wait test
+RUN import time
+RUN start = time.time()
+SLEEP .1
+RUN end = time.time()
+RUN delta = end - start
+RUN epsilon = abs(delta - .1)
+PRINTP epsilon
+FAIL epsilon > .001
+## large wait test
+RUN start = time.time()
+SLEEP 10
+RUN end = time.time()
+RUN delta = end - start
+RUN epsilon = abs(delta - 10)
+PRINTP epsilon
+FAIL epsilon > .02
+## very large wait test
+RUN start = time.time()
+SLEEP 100
+RUN end = time.time()
+RUN delta = end - start
+RUN epsilon = abs(delta - 100)
+PRINTP epsilon
+ASSERT epsilon < .15