review straylight edits to rebase -- add straylight.check

python/lsst/obs/subaru/strayLight/yStrayLight.py

@@ -56,18 +56,26 @@ def readIsrData(self, dataRef, rawExposure):
         # Note that this is run only in Gen2; in Gen3 we will rely on having
         # a proper butler-recognized dataset type with the right validity
         # ranges (though this has not yet been implemented).
-        detId = rawExposure.getDetector().getId()
-        if not self.checkFilter(rawExposure):
-            # No correction to be made
+        if not self.check(rawExposure):
             return None
+
+        return SubaruStrayLightData(dataRef.get("yBackground_filename")[0])
+
+    def check(self, exposure):
+        # Docstring inherited from StrayLightTask.check.
+        detId = exposure.getDetector().getId()
+        if not self.checkFilter(exposure):
+            # No correction to be made
+            return False
         if detId in range(104, 112):
             # No correction data: assume it's zero
-            return None
-        if rawExposure.getInfo().getVisitInfo().getDate().toPython() >= datetime.datetime(2018, 1, 1):
+            return False
+        if exposure.getInfo().getVisitInfo().getDate().toPython >= datetime.datetime(2018, 1, 1):
             # LEDs causing the stray light have been covered up.
             # We believe there is no remaining stray light.
-            return None
-        return SubaruStrayLightData(dataRef.get("yBackground_filename")[0])
+            return False
+
+        return True
 
     def run(self, exposure, strayLightData):
         """Subtract the y-band stray light
@@ -87,22 +95,14 @@ def run(self, exposure, strayLightData):
             An opaque object that contains any calibration data used to
             correct for stray light.
         """
-        exposureMetadata = exposure.getMetadata()
-        detId = exposure.getDetector().getId()
-
-        if not self.checkFilter(exposure):
-            self.log.info("No straylight correction needed.")
-            return None
-        if detId in range(104, 112):
-            self.log.info("No straylight correction needed.")
-            return None
-        if exposure.getInfo().getVisitInfo().getDate().toPython() >= datetime.datetime(2018, 1, 1):
-            self.log.info("No straylight correction needed.")
+        if not self.check(exposure):
             return None
 
         if strayLightData is None:
             raise RuntimeError("No strayLightData supplied for correction.")
 
+        exposureMetadata = exposure.getMetadata()
+        detId = exposure.getDetector().getId()
         if self.config.doRotatorAngleCorrection:
             angleStart, angleEnd = inrStartEnd(exposure.getInfo().getVisitInfo())
             self.log.debug(