[RaphaelFakhri]

to_yaml_string reset its list item counter on every key line that is not a list item. When a list item has more than one key, the counter is back at 0 before the next item starts, so every item after the first is looked up as item 0. Docs that exist only for a later item are then dropped from the generated YAML, for example the fields of an Option that is None in the first item and Some in a later one. This affects Cli's --generate output and to_yaml_file with both the serde_yaml and serde-saphyr backends.

This change tracks the next item index for each enclosing list by its indentation. A list item line continues the list at its indentation and ends any list nested in the previous item. A key line at or left of a list's dash ends that list.

Before

  - name: bar
    # Optional field
    optional:
      a: 1
      b: 2
      c: 3

After

  - name: bar
    # Optional field
    optional:
      # A field, which is named the same as another field.
      a: 1
      # multi-line
      # doc comment
      b: 2
      c: 3

Testing

• Added vec_items_with_different_fields to foundations/tests/settings.rs, with expected output for both YAML backends. It fails without the fix and passes with it.
• cargo test -p foundations --no-default-features --features settings --test settings: 13 passed, with and without --features serde-saphyr.
• cargo fmt --all -- --check and the clippy command from AGENTS.md (on --lib --test settings) are clean.

Fixes #282