From aa2129fb4ec2e9fd61dd9f06a2316cf339385730 Mon Sep 17 00:00:00 2001
From: John Miller <jmiller@rjmetrics.com>
Date: Wed, 17 Oct 2018 09:28:08 -0400
Subject: [PATCH 1/2] Adds should_sync_field to utils

---
 singer/__init__.py |  1 +
 singer/utils.py    | 74 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/singer/__init__.py b/singer/__init__.py
index 874ac39..2ad7333 100644
--- a/singer/__init__.py
+++ b/singer/__init__.py
@@ -7,6 +7,7 @@
     strftime,
     strptime,
     update_state,
+    should_sync_field,
 )
 
 from singer.logger import (
diff --git a/singer/utils.py b/singer/utils.py
index bc8d844..8c09a72 100644
--- a/singer/utils.py
+++ b/singer/utils.py
@@ -195,3 +195,77 @@ def wrapped(*args, **kwargs):
                 raise
         return wrapped
     return decorator
+
+
+def should_sync_field(inclusion, selected, default=False):
+    """
+    Returns True if a field should be synced.
+
+    inclusion: automatic|available|unsupported
+    selected: True|False|None
+    default: (default: False) True|False
+
+
+    "automatic" inclusion always returns True:
+
+    >>> should_sync_field("automatic", None, False)
+    True
+    >>> should_sync_field("automatic", True, False)
+    True
+    >>> should_sync_field("automatic", False, False)
+    True
+    >>> should_sync_field("automatic", None, True)
+    True
+    >>> should_sync_field("automatic", True, True)
+    True
+    >>> should_sync_field("automatic", False, True)
+    True
+
+
+    "unsupported" inclusion always returns False
+
+    >>> should_sync_field("unsupported", None, False)
+    False
+    >>> should_sync_field("unsupported", True, False)
+    False
+    >>> should_sync_field("unsupported", False, False)
+    False
+    >>> should_sync_field("unsupported", None, True)
+    False
+    >>> should_sync_field("unsupported", True, True)
+    False
+    >>> should_sync_field("unsupported", False, True)
+    False
+
+    "available" inclusion uses the selected value when set
+    >>> should_sync_field("available", True, False)
+    True
+    >>> should_sync_field("available", False, False)
+    False
+    >>> should_sync_field("available", True, True)
+    True
+    >>> should_sync_field("available", False, True)
+    False
+
+    "available" inclusion uses the default value when selected is None
+
+    >>> should_sync_field("available", None, False)
+    False
+    >>> should_sync_field("available", None, True)
+    True
+    """
+    # always select automatic fields
+    if inclusion == "automatic":
+        return True
+
+    # never select unsupported fields
+    if inclusion == "unsupported":
+        return False
+
+    # at this point inclusion == "available"
+    # selected could be None, otherwise use the value of selected
+    if selected is not None:
+        return selected
+
+    # if there was no selected value, use the default
+    return default

From 339d2aedca925984127861e474e623b5fa71880e Mon Sep 17 00:00:00 2001
From: John Miller <jmiller@rjmetrics.com>
Date: Wed, 17 Oct 2018 09:30:14 -0400
Subject: [PATCH 2/2] whitespace

---
 singer/utils.py | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/singer/utils.py b/singer/utils.py
index 8c09a72..81944fe 100644
--- a/singer/utils.py
+++ b/singer/utils.py
@@ -205,9 +205,7 @@ def should_sync_field(inclusion, selected, default=False):
     selected: True|False|None
     default: (default: False) True|False
 
-
     "automatic" inclusion always returns True:
-
     >>> should_sync_field("automatic", None, False)
     True
     >>> should_sync_field("automatic", True, False)
@@ -223,7 +221,6 @@ def should_sync_field(inclusion, selected, default=False):
 
 
     "unsupported" inclusion always returns False
-
     >>> should_sync_field("unsupported", None, False)
     False
     >>> should_sync_field("unsupported", True, False)
@@ -248,7 +245,6 @@ def should_sync_field(inclusion, selected, default=False):
     False
 
     "available" inclusion uses the default value when selected is None
-
     >>> should_sync_field("available", None, False)
     False
     >>> should_sync_field("available", None, True)