Source S3: fix discovery issues

[davydov-d]

What

https://github.com/airbytehq/oncall/issues/1664
https://github.com/airbytehq/oncall/issues/1652

How

This PR actually fixes two different problems:

• Return empty schema if no files found during discovery
• Do not infer data types when user schema is applied (see more in code comment)

🚨 User Impact 🚨

The second fix will only impact connections with:

• File type = CSV and
• User enforced schema and
• Large files and small block size

Some data may change it's type but still it shouldn't break syncs (see more in code comment)

[davydov-d]

/test connector=connectors/source-s3

🕑 connectors/source-s3 https://github.com/airbytehq/airbyte/actions/runs/4440330375
✅ connectors/source-s3 https://github.com/airbytehq/airbyte/actions/runs/4440330375
Python tests coverage:

Name                                                              Stmts   Miss  Cover
-------------------------------------------------------------------------------------
source_s3/source_files_abstract/storagefile.py                       23      0   100%
source_s3/source_files_abstract/spec.py                              55      0   100%
source_s3/source_files_abstract/formats/parquet_spec.py               9      0   100%
source_s3/source_files_abstract/formats/jsonl_spec.py                13      0   100%
source_s3/source_files_abstract/formats/csv_spec.py                  16      0   100%
source_s3/source_files_abstract/formats/avro_spec.py                  5      0   100%
source_s3/source.py                                                  27      0   100%
source_s3/exceptions.py                                              10      0   100%
source_s3/__init__.py                                                 2      0   100%
source_s3/source_files_abstract/formats/parquet_parser.py            64      2    97%
source_s3/source_files_abstract/formats/abstract_file_parser.py      41      2    95%
source_s3/stream.py                                                  43      3    93%
source_s3/s3file.py                                                  41      3    93%
source_s3/source_files_abstract/formats/avro_parser.py               39      3    92%
source_s3/source_files_abstract/formats/jsonl_parser.py              53      5    91%
source_s3/source_files_abstract/file_info.py                         26      3    88%
source_s3/source_files_abstract/formats/csv_parser.py               130     16    88%
source_s3/source_files_abstract/source.py                            41      7    83%
source_s3/source_files_abstract/stream.py                           198     35    82%
source_s3/s3_utils.py                                                20      4    80%
source_s3/utils.py                                                   31     10    68%
-------------------------------------------------------------------------------------
TOTAL                                                               887     93    90%
Name                                                              Stmts   Miss  Cover
-------------------------------------------------------------------------------------
source_s3/source_files_abstract/formats/parquet_spec.py               9      0   100%
source_s3/source_files_abstract/formats/jsonl_spec.py                13      0   100%
source_s3/source_files_abstract/formats/csv_spec.py                  16      0   100%
source_s3/source_files_abstract/formats/avro_spec.py                  5      0   100%
source_s3/s3_utils.py                                                20      0   100%
source_s3/__init__.py                                                 2      0   100%
source_s3/source_files_abstract/storagefile.py                       23      1    96%
source_s3/stream.py                                                  43      3    93%
source_s3/source_files_abstract/stream.py                           198     14    93%
source_s3/s3file.py                                                  41      3    93%
source_s3/source_files_abstract/formats/abstract_file_parser.py      41      4    90%
source_s3/source.py                                                  27      4    85%
source_s3/source_files_abstract/formats/csv_parser.py               130     40    69%
source_s3/source_files_abstract/file_info.py                         26      8    69%
source_s3/utils.py                                                   31     10    68%
source_s3/exceptions.py                                              10      4    60%
source_s3/source_files_abstract/source.py                            41     18    56%
source_s3/source_files_abstract/spec.py                              55     31    44%
source_s3/source_files_abstract/formats/jsonl_parser.py              53     32    40%
source_s3/source_files_abstract/formats/avro_parser.py               39     25    36%
source_s3/source_files_abstract/formats/parquet_parser.py            64     44    31%
-------------------------------------------------------------------------------------
TOTAL                                                               887    241    73%

Build Passed

Test summary info:

=========================== short test summary info ============================
SKIPPED [1] ../usr/local/lib/python3.9/site-packages/connector_acceptance_test/tests/test_core.py:100: The previous and actual specifications are identical.
SKIPPED [5] ../usr/local/lib/python3.9/site-packages/connector_acceptance_test/tests/test_core.py:509: The previous and actual discovered catalogs are identical.
================== 95 passed, 6 skipped in 270.05s (0:04:30) ===================

[bnchrch]

One small nit but otherwise LGTM.

Friendly reminder to Run CAT before publishing.

[davydov-d]

/publish connector=connectors/source-s3

🕑 Publishing the following connectors:
connectors/source-s3
https://github.com/airbytehq/airbyte/actions/runs/4441038122

Connector	Did it publish?	Were definitions generated?
connectors/source-s3	✅	✅

if you have connectors that successfully published but failed definition generation, follow step 4 here ▶️