From 178247e2a7526cdccf66accd6267ec377fa7b901 Mon Sep 17 00:00:00 2001
From: RuslanBergenov <bergenov@ualberta.ca>
Date: Wed, 18 Aug 2021 16:35:51 -0600
Subject: [PATCH] refactor: simplified create_valid_bigquery_field_name()
 function

---
 .github/workflows/python-package.yml    |  2 +-
 target_bigquery/schema.py               | 61 ++++++++-----------------
 target_bigquery/validate_json_schema.py |  6 +--
 3 files changed, 23 insertions(+), 46 deletions(-)

diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 29ec00c..83bf842 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -24,7 +24,7 @@ env:
 
 on:
   push:
-    branches: [ development-ci-cd-workflow, development, master ]
+    branches: [ development-ci-cd-workflow, development, master, development-refactor-bigquery-field-name-function ]
   pull_request:
     branches: [ master ]
 
diff --git a/target_bigquery/schema.py b/target_bigquery/schema.py
index ccce3be..01124cb 100755
--- a/target_bigquery/schema.py
+++ b/target_bigquery/schema.py
@@ -31,7 +31,7 @@ def cleanup_record(schema, record):
     elif isinstance(record, dict):
         nr = {}
         for key, value in record.items():
-            nkey = bigquery_transformed_key(key)
+            nkey = create_valid_bigquery_field_name(key)
             nr[nkey] = cleanup_record(schema, value)
         return nr
 
@@ -39,7 +39,7 @@ def cleanup_record(schema, record):
         raise Exception(f"unhandled instance of record: {record}")
 
 
-def bigquery_transformed_key(key):
+def create_valid_bigquery_field_name(field_name):
     """
     Clean up / prettify field names, make sure they match BigQuery naming conventions.
     
@@ -56,45 +56,22 @@ def bigquery_transformed_key(key):
     :param key: JSON field name
     :return: cleaned up JSON field name
     """
-    remove_list = [" ",
-                   "!",
-                   "\"",
-                   "#",
-                   "$",
-                   "%",
-                   "&",
-                   "'",
-                   "(",
-                   ")",
-                   "*",
-                   "+",
-                   ",",
-                   "-",
-                   ".",
-                   "/",
-                   ":",
-                   ";",
-                   "<",
-                   "=",
-                   ">",
-                   "?",
-                   "@",
-                   "\\",
-                   "]",
-                   "^",
-                   "`",
-                   "|",
-                   "}",
-                   "~"]
-
-    for c in remove_list:
-        key = key.replace(c, "_")
-
-    if re.match(r"^\d", key):
-        key = "_" + key
-
-    return key
 
+    cleaned_up_field_name = ""
+
+    # if char is alphanumeric (either letters or numbers), append char to our string
+    for char in field_name:
+        if char.isalnum():
+            cleaned_up_field_name += char
+        else:
+            # otherwise, replace it with underscore
+            cleaned_up_field_name += "_"
+
+    # if field starts with digit, prepend it with underscore
+    if cleaned_up_field_name[0].isdigit():
+        cleaned_up_field_name = "_%s" % cleaned_up_field_name
+
+    return cleaned_up_field_name[:300] # trim the string to the first x chars
 
 def prioritize_one_data_type_from_multiple_ones_in_any_of(field_property):
     """
@@ -248,7 +225,7 @@ def build_field(field_name, field_property):
     if not ("items" in field_property and "properties" in field_property["items"]) and not (
             "properties" in field_property):
 
-        return (SchemaField(name=bigquery_transformed_key(field_name),
+        return (SchemaField(name=create_valid_bigquery_field_name(field_name),
                             field_type=convert_field_type(field_property),
                             mode=determine_field_mode(field_name, field_property),
                             description=None,
@@ -266,7 +243,7 @@ def build_field(field_name, field_property):
                                                                    ).items():
             processed_subfields.append(build_field(subfield_name, subfield_property))
 
-        return (SchemaField(name=bigquery_transformed_key(field_name),
+        return (SchemaField(name=create_valid_bigquery_field_name(field_name),
                             field_type=convert_field_type(field_property),
                             mode=determine_field_mode(field_name, field_property),
                             description=None,
diff --git a/target_bigquery/validate_json_schema.py b/target_bigquery/validate_json_schema.py
index 89316b5..0146c0a 100644
--- a/target_bigquery/validate_json_schema.py
+++ b/target_bigquery/validate_json_schema.py
@@ -1,6 +1,6 @@
 import re
 import singer
-from target_bigquery.schema import bigquery_transformed_key
+from target_bigquery.schema import create_valid_bigquery_field_name
 
 LOGGER = singer.get_logger()
 
@@ -107,7 +107,7 @@ def build_field_list(schema):
         for field_name, field_property in schema.get("properties", schema.get("items", {}).get("properties", {})).items():
             if not ("items" in field_property and "properties" in field_property["items"]) \
                     and not ("properties" in field_property):
-                key = bigquery_transformed_key(field_name.upper())
+                key = create_valid_bigquery_field_name(field_name.upper())
                 if not f_dict.get(key):
                     f_dict[key] = [field_name]
                 else:
@@ -116,7 +116,7 @@ def build_field_list(schema):
             elif ("items" in field_property and "properties" in field_property["items"]) \
                     or ("properties" in field_property):
                 nd = build_field_list(field_property)
-                key = bigquery_transformed_key(field_name.upper())
+                key = create_valid_bigquery_field_name(field_name.upper())
                 for k, v in nd.items():
                     if not f_dict.get(f"{key}.{k}"):
                         f_dict[f"{key}.{k}"] = [f"{field_name}.{i}" for i in v]