Types of changes

Internal changes:

• Refactor (prefix: refactor - non-breaking change which only improves the design or structure of existing code, and making no changes to its external behaviour)
• Tests (prefix: test - additions and improvements to unit tests and the smoke tests)

Description

• Convert parseFileContent() in to a class FileParser.
• By making some parameters fields, I can start extracting methods that have a reasonable number of parameters themselves.
• Initially, the big win is the extraction of FileParser.parseFileContent(), which greatly reduced the complexity of FileParser.parseLine()

Note that some of the new fields may turn out to be redundant - but I wanted to merge progress so far, why the diffs are still moderately readable.

Note that because of a change in indentation in some of this code, the diffs are easier to read in this Web UI if enabling GitHub's 'Hide whitespace' option:

Motivation and Context

Preparing to fix:

• 'show tree' does not render non-task checkboxes #3170

How has this been tested?

• Automated tests
• Exploratory testing

Checklist

• My code follows the code style of this project and passes yarn run lint.
• My change has adequate Unit Test coverage.

Terms

• My contribution follows this project's contributing guide
• I agree to follow this project's Code of Conduct