Don't use the versions file for tools installed via NPM

[thomashoneyman]

The versions file exists to avoid rate limits imposed by GitHub when getting the latest release for various tools via the GitHub API. However, if a user specifies they want the latest tool and the tool is installed via NPM, then we should skip the versions file and just NPM install the latest -- we don't get rate limited on that.

[thomashoneyman]

This function decides whether to fetch an exact version of a tool (because the user specified an exact version) or to look up the latest version in the versions file:

setup-purescript/src/Setup/BuildPlan.purs

Lines 54 to 80 in 915bfb6

	-- | Resolve the exact version to provide for a tool in the environment, based
	-- | on the action.yml file.
	resolve :: Json -> Tool -> ExceptT Error Effect (Maybe { tool :: Tool, version :: Version })
	resolve versionsContents tool = do
	let key = Key.fromTool tool
	field <- getVersionField key
	case field of
	Nothing -> pure Nothing
	Just (Exact v) -> liftEffect do
	Core.info "Found exact version"
	pure (pure { tool, version: v })
	Just Latest -> liftEffect do
	Core.info $ fold [ "Fetching latest tag for ", Tool.name tool ]
	let
	version = lmap printJsonDecodeError $ (_ .: Tool.name tool) =<< decodeJson versionsContents
	parse = lmap parseErrorMessage <<< Version.parseVersion
	case parse =<< version of
	Left e -> do
	Core.setFailed $ fold [ "Unable to parse version: ", e ]
	throwError $ error "Unable to complete fetching version."
	Right v -> do
	pure (pure { tool, version: v })

However, if the InstallMethod for a tool is NPM:

setup-purescript/src/Setup/Data/Tool.purs

Lines 78 to 80 in 915bfb6

	-- | How a tool will be installed: either a tarball from a URL, or an NPM package
	-- | at a particular version.
	data InstallMethod = Tarball TarballOpts | NPM NPMPackage

...then we should skip the versions file altogether and just NPM install the tool at its latest version according to NPM:

setup-purescript/src/Setup/Data/Tool.purs

Lines 94 to 148 in 915bfb6

	installMethod :: Tool -> Version -> InstallMethod
	installMethod tool version = do
	let
	toolName = name tool
	toolRepo = repository tool
	formatArgs = { repo: toolRepo, tag: formatTag, tarball: _ }
	formatGitHub' = formatGitHub <<< formatArgs
	unsafeVersion str = fromRight' (\_ -> unsafeCrashWith "Unexpected Left") $ parseVersion str
	executableName = case platform of
	Windows -> toolName <> ".exe"
	_ -> toolName
	case tool of
	PureScript -> Tarball
	{ source: formatGitHub' case platform of
	Windows -> "win64"
	Mac -> "macos"
	Linux -> "linux64"
	, getExecutablePath: \p -> Path.concat [ p, "purescript", executableName ]
	}
	Spago -> Tarball
	{ source: formatGitHub'
	-- Spago has changed naming conventions from version to version
	if version >= unsafeVersion "0.18.1" then case platform of
	Windows -> "Windows"
	Mac -> "macOS"
	Linux -> "Linux"
	else if version == unsafeVersion "0.18.0" then case platform of
	Windows -> "windows-latest"
	Mac -> "macOS-latest"
	Linux -> "linux-latest"
	else case platform of
	Windows -> "windows"
	Mac -> "osx"
	Linux -> "linux"
	, getExecutablePath: \p -> Path.concat [ p, executableName ]
	}
	Psa ->
	NPM ("purescript-psa@" <> Version.showVersion version)
	PursTidy ->
	NPM ("purs-tidy@" <> Version.showVersion version)
	Zephyr -> Tarball
	{ source: formatGitHub' $ case platform of
	Windows -> "Windows"
	Mac -> "macOS"
	Linux -> "Linux"
	, getExecutablePath: \p -> Path.concat [ p, "zephyr", executableName ]
	}

Currently that only covers psa and purs-tidy.

[pete-murphy]

Does something like this (#24) make sense as a possible fix?