yaml_agent_string() returns the yaml string

[yjunechoe]

Summary

Resolves #609

Now:

yaml <- create_agent(~ small_table) %>% 
  yaml_agent_string()
#> type: agent
#> tbl: ~small_table
#> tbl_name: ~small_table
#> label: '[2025-03-24|14:54:42]'
#> lang: en
#> locale: en
#> steps: []

yaml
#> [1] "type: agent\ntbl: ~small_table\ntbl_name: ~small_table\nlabel: '[2025-03-24|14:54:42]'\nlang: en\nlocale: en\nsteps: []\n"

cat(yaml)
#> type: agent
#> tbl: ~small_table
#> tbl_name: ~small_table
#> label: '[2025-03-24|14:54:42]'
#> lang: en
#> locale: en
#> steps: []

Previously:

yaml <- create_agent(~ small_table) %>% 
  yaml_agent_string()
#> type: agent
#> tbl: ~small_table
#> tbl_name: ~small_table
#> label: '[2025-03-19|12:30:03]'
#> lang: en
#> locale: en
#> steps: []

yaml
#> NULL

Related GitHub Issues and PRs

• Ref: yaml_agent_string() could return the yaml string #609

Checklist

• I understand and agree to the Code of Conduct.
• I have listed any major changes in the NEWS.
• I have added testthat unit tests to tests/testthat for any new functionality.

[rich-iannone]

LGTM!