featuremap.txt

Configuration (OK)
	OCaml settings
		Goal is not to reproduce OCaml testsuite, just that settings are applied correctly and that the few Merlin specific behavior are affected.
		include_dirs
		no_std_include
			check that it is possible to provide an alternative stdlib
		unsafe
			check that merlin is subject to the same syntactic quirks as OCaml
		classic
			write code that mixes different kind of arguments, check errors
		principal
			write non-principal code, check errors
		threads
			check that Thread/Mutex/Event libraries are found if the flag is specified
		recursive_types
			write dubious code that wouldn't typecheck without it
		strict_sequence
			check that 5; () fails
		applicative_functors
			check that non-applicative functors are rejected, check quirks in Parser
		unsafe_string
			check that environment is setup correctly with and without unsafe string
			check that Bytes and String deprecation warning are reported appropriately
		nopervasives
			figure wtf happens in this case ?!
		strict_formats
			check it conforms to OCaml behavior, what is this expected to do?
		open_modules
			check environment is initialized as it should
		ppx
			check Ast is rewritten as it should
			ensure graceful degradation if ppx is missing or broken
			check composition of multiple ppx work as expected
		pp
			check frontend/reader is affected as it should
		warnings
			check that a few warnings are treated properly
		reals_paths / Short-path
	Findlib configuration
		conf
			check that it overrides location of findlib.conf
			check behavior when file is missing or invalid (directory, wrong permission)
		path
			check that it actually adds new path to the findlib package directories
	Merlin settings
		TODO: define command line flags for each of these settings
		build_path / source_path / cmi_path / cmt_path
			specify which behavior are affected by each path variable
			check that each variable is considered for corresponding lookups
		extensions
			check that corresponding extensions are enabled in lexer / parser / typer
		suffixes
			specify which behavior should be affected by suffixes
			check that .ml(i) and .re(i) are correctly handled by default
		stdlib
			check that it is possible to use merlin with a different installation of OCaml
			ensure graceful degradation if stdlib is incorrect
		reader
			ensure this setting is not ignored
		dot_merlin
			specify the format for good
			ensure all features are parsed and affects configuration
			ensure recursive resolution is working properly
		packages
			ensure build path is updated correctly
			ensure graceful degradation when loading unknown or invalid packages
			ensure that ppxs specified by packages are loaded correctly
				ppx path should be resolved relative to package directory
	Query settings
		directory
			ensure this setting takes precedence over process working directory
		filename
			TODO: remove Msource.filename?
		terminal_width
			check that pretty printer / error behavior take this into account :)
			or completely remove it?
		verbosity
			check that various verbosity sensitive queries are affected
Queries (WIP)
	Case analysis (destruct)
		On a pattern
			If exhaustive
				Try and split the thing under the cursor (works
				on variables and wildcards) into subpatterns
			If not-exhaustive
				Make it exhaustive
		On an expression [e]
			If it is a module
				expand into "let module ..."
			If it is a variant or record type
				replace by [match e with <cases>]
	Completion
		Normal
			Candidate enumeration
				Polymorphic variants
				Values
				Value constructors
				Type constructors
				Modules
					Signature expansion affected by verbosity
				Module types
				Record labels
		Record fields
			Normal
			After module path
		Method completion
		Sorting
			By categories
				Expression
				Structure
				Pattern
				Module
				Module types
				Signature 
				Type
			By unification cost
			By number of "arrows"
		Arguments
			Type-directed
			For infix operator
			Labelled argument
			Optional argument
		Expansion / spell checking
			Path prefixes completion
			Spell correction
		Global modules
		Filtering
			Hidden namespace '_'
			Janestreet modules containing '__'
	Document
		check external doc comments are reported appropriately
		check internal doc comments are reported appropriately
	Dump
		parsetree
		printast
		env / fullenv
		browse
		tokens
		flags
		warnings
		exn
		paths
	Errors
		Sources
			Lexer
			Parser
			Typer
				If a CMI is missing, only report this error (FIXME: these errors?)
				Filter out type errors after a syntax error, they are likely to be noise
				Top-level errors shouldn't escape
		Sort by position
		TODO: find a way to measure recovery quality
	Extensions
		Meta OCaml
		Lwt
	Findlib list
		Check that custom findlib setups are supported
		Fail gracefully if findlib not available? (JST)
	Jump
	Locate
	Occurrences
		Look in the appropriate namespace, check correct behavior for each
			Values
			Constructors
			Types
			Modules
		What is the behavior when exiting/entering a module
			Plain identifier when referred to from outside the module?
			Qualified identifier when referred to from inside the module
	Outline
	Shape
	Type enclosing
		String argument (expro) is a bit redundant: only position should be provided.
		↑ Wasn't that used to be able to do things like ":TypeOf FooBar.S"?
		↓ See below, the string argument is used to approximate where the cursor is
      (in the middle of a path or even a path component), since locations are
      only stored at the granularity of one path
	Type expression
		Ensure expression is typed in the right environment
		Explain how verbosity affects results
	Which (find source files)
		With ext
		Path
Reader (WIP)
	check behaviors for builtin, -pp and external frontends
	Lexer
		Reconstruct identifiers
		Decompose path components into tokens (TODO)
		Check comments are reported appropriately
	Parser
		check support for ML & MLI
	Pretty-printer
		of parsetree (for destruct)
		of outcometree (for completion & error report)
		support for external readers