Fix nullable constraint on array fields

Fixes #4

.gitignore

@@ -11,8 +11,7 @@ __pycache__/
 _local
 
 # Output directory of the package itself
-**/output
-**/target/bq2dbt
+/target
 
 # Distribution / packaging
 build/

README.md

@@ -17,9 +17,14 @@ I know this looks like something the codegen dbt package could do, but it was fa
 
 We used this script to convert an existing project with missing contracts and with `SELECT *` statements to something for robust and implicit, and with existing tables in BigQuery. This is the main purpose of this.
 
-# Install the script localy
+# Instal from source
 
-Just use pip:
+
+```
+pip install .
+```
+
+# Install from Github
 
 ```
 # Latest version

bq2dbt/bq2dbt.py

@@ -128,11 +128,13 @@ def bq2dbt():
             "description": field.description or ""
         }
         if field.is_nullable == 'NO':
-            field_info = {**field_info, **{
-                "constraints": [
-                    {"type": "not_null"}
-                ]
-            }}
+            # BigQuery says array cannot be null, but they can and they don't support not_null constraint
+            if data_type not in ['ARRAY']:
+                field_info = {**field_info, **{
+                    "constraints": [
+                        {"type": "not_null"}
+                    ]
+                }}
 
         yaml_data["models"][0]["columns"].append(field_info)
         if '.' not in field.field_path: