Clue compilation changes and DOM features

[pvspain]

compile-clue.js

• Expand clue compilation to full clue object, including x,y,answer properties.
• Test for clue structure validateClueStructure - properties and types.Expand test coverage for clue compilation.
• Add support for optional properties (answer) in clue validation.
• TODO: Add solution to optional properties for answer checking features.
• Add direction flag argument to compileClue and add test coverage for same.
• Localise trapping of regex parsing errors - better diagnostics.
• Tweak clueGroup in clueRegex to be a greedy match (to allow parentheses in clue text).
• Set answer value in compileClue from clueDefinition.
• Tweak exception text in compileClue to 'plainer' English.
• Rename answerSegmentsText as answerLengthText.
• Rename return element compileClue.isAcrossClue as compileClue.isAcross as context (clue) will always be attached.

compile-clue.specs.js

• Refactor all tests for clue objects.
• Define test case data as an object/associative-array with descriptive keys.
• Add tests for malformed multi-word answers and multi-segment numbers.
• Add additional tests for optional clue properties.

compile-crossword.js

• FIX: buildCellArray2D (Error triggered when width <> height) and rename variables for clarity.
• Rename answerSegmentsText as answerLengthText.
• Rename model as crosswordModel to remove ambiguity with clueModel.
• Rename across as isAcrossClue to improve clarity.

albreich_4.json

• FIX: missing label terminators in (10 across)

helpers.js

• Migrate trace function from crossworddom.js.
• Add memoize function.

crossworddom.js

FEATURE: Add multi-segment clue support to TAB key handler.

• Add private accessors #window and #document
• Add helpers cell(), cellElement() and inputElement()
• Extract window event handler #onWindowResize and remove from window in destroy()

FEATURE: Add direction toggle on click event

• Same behaviour as ENTER key.
• Add event listener for "click" events.
• Introduce state for current cell to test against event cell in click event handler.
• Extracted function swapClueDirection for common logic in click event handler and ENTER key press.

CHORE:

• Reduce exceptions in .eslintrc.yml#no-params-reassign:ignorePropertyModifications

CHORE:

• Add in-situ eslint directives for param reassignment overrides.

DOC:

• Check implemented feature - onclick handling on cell intersection.
• Change in-situ link to footnote.

[dwmkerr]

This is looking amazing thanks @pvspain!

[pvspain]

Thanks @dwmkerr :)