[CT-273] [Bug] modifying snapshot files with multiple snapshots causes error (partial parsing)

[gshank]

If you modify a snapshot file with multiple snapshot blocks, and then do 'dbt run', you see the error "dbt found two resources with the name "date_orders_snapshot". Running with "--no-partial-parse" will re-parse the entire project and then you can run again.

The partial parsing code does not handle multiple snapshot blocks.

[jtcohen6]

Nice find! Could this also:

• Fix the same bug for macros: [Bug] Macro added twice during partial parsing  #4233
• Happen for docs blocks? The bugs we've heard about have been more around, a docs block being missed, than accidentally added twice