Fix parsing of subcommands

README.md

@@ -209,7 +209,7 @@ Available options:
 Available commands:
   init                     Initialize a Nix project. Existing files won't be
                            modified.
-  add                      Add dependency
+  add                      Add a GitHub dependency
   show                     
   update                   Update dependencies
   modify                   Modify dependency
@@ -226,11 +226,11 @@ Examples:
   niv add NixOS/nixpkgs-channels -n nixpkgs -b nixos-19.03
   niv add my-package -v alpha-0.1 -t http://example.com/archive/<version>.zip
 
-Usage: niv add [-n|--name NAME] PACKAGE ([-a|--attribute KEY=VAL] |
+Usage: niv add PACKAGE [-n|--name NAME] ([-a|--attribute KEY=VAL] |
                [-s|--string-attribute KEY=VAL] | [-b|--branch BRANCH] |
                [-o|--owner OWNER] | [-r|--repo REPO] | [-v|--version VERSION] |
                [-t|--template URL] | [-T|--type TYPE])
-  Add dependency
+  Add a GitHub dependency
 
 Available options:
   -n,--name NAME           Set the package name to <NAME>
@@ -250,8 +250,8 @@ Available options:
   -h,--help                Show this help text
 
 Experimental commands:
-  git                      Echo a message back
+  git                      Add a git dependency. Experimental.
-  github                   Add dependency
+  github                   Add a GitHub dependency
 
 ```
 

src/Niv/Cli.hs

@@ -12,7 +12,6 @@ import Control.Applicative
 import Control.Monad
 import Data.Aeson ((.=))
 import Data.Char (isSpace)
-import Data.Functor
 import Data.HashMap.Strict.Extended
 import Data.Hashable (Hashable)
 import Data.String.QQ (s)
@@ -141,38 +140,67 @@ cmdInit = do
 parseCmdAdd :: Opts.ParserInfo (IO ())
 parseCmdAdd =
     Opts.info
-      ((sp <|> shortcutGitHub) <**> Opts.helper) $
+      ((parseCommands <|> parseShortcuts) <**> Opts.helper) $
       (description githubCmd)
   where
-    shortcutGitHub = uncurry (cmdAdd (updateCmd githubCmd)) <$> parseArgs
+    -- XXX: this should parse many shortcuts (github, git). Right now we only
+    -- parse GitHub because the git interface is still experimental.  note to
+    -- implementer: it'll be tricky to have the correct arguments show up
+    -- without repeating "PACKAGE PACKAGE PACKAGE" for every package type.
+    parseShortcuts = parseShortcut githubCmd
+    parseShortcut cmd = uncurry (cmdAdd (updateCmd cmd)) <$> (parseShortcutArgs cmd)
+    parseCmd cmd = uncurry (cmdAdd (updateCmd cmd)) <$> (parseCmdArgs cmd)
     parseCmdAddGit =
-      Opts.info
+      Opts.info (parseCmd gitCmd <**> Opts.helper) (description gitCmd)
-        (uncurry (cmdAdd (updateCmd gitCmd)) <$> parseArgs <**> Opts.helper) $
-        (description gitCmd)
     parseCmdAddGitHub =
-      Opts.info
+      Opts.info (parseCmd githubCmd <**> Opts.helper) (description githubCmd)
-        (uncurry (cmdAdd (updateCmd githubCmd)) <$> parseArgs <**> Opts.helper) $
+    parseCommands = Opts.subparser
-        (description githubCmd)
-
-    sp = Opts.subparser
         ( Opts.hidden <>
           Opts.commandGroup "Experimental commands:" <>
           Opts.command "git" parseCmdAddGit <>
           Opts.command "github" parseCmdAddGitHub
         )
 
-    parseArgs :: Opts.Parser (PackageName, Attrs)
+-- | only used in shortcuts (niv add foo/bar ...) because PACKAGE is NOT
-    parseArgs = collapse <$> parseNameAndShortcut <*> (parsePackageSpec githubCmd)
+-- optional
+parseShortcutArgs :: Cmd -> Opts.Parser (PackageName, Attrs)
+parseShortcutArgs cmd = collapse <$> parseNameAndShortcut <*> parsePackageSpec cmd
+  where
+    collapse specAndName pspec = (pname, specToLockedAttrs $ pspec <> baseSpec)
+      where
+        (pname, baseSpec) = case specAndName of
+          ((_, spec), Just pname') -> (pname', PackageSpec spec)
+          ((pname', spec), Nothing) -> (pname', PackageSpec spec)
     parseNameAndShortcut =
       (,) <$>
-        optName <*>
+        Opts.argument
-        (Opts.strArgument (Opts.metavar "PACKAGE") <&> (parseShortcut githubCmd))
+          (Opts.maybeReader (parseCmdShortcut cmd . T.pack))
-    -- collaspe a "name or shortcut" with package spec
+          (Opts.metavar "PACKAGE") <*>
-    collapse nameAndSpec pspec = (pname, specToLockedAttrs $ pspec <> baseSpec)
+        optName
+    optName = Opts.optional $ PackageName <$> Opts.strOption
+      ( Opts.long "name" <>
+        Opts.short 'n' <>
+        Opts.metavar "NAME" <>
+        Opts.help "Set the package name to <NAME>"
+      )
+
+-- | only used in command (niv add <cmd> ...) because PACKAGE is optional
+parseCmdArgs :: Cmd -> Opts.Parser (PackageName, Attrs)
+parseCmdArgs cmd = collapse <$> parseNameAndShortcut <*> parsePackageSpec cmd
+  where
+    collapse specAndName pspec = (pname, specToLockedAttrs $ pspec <> baseSpec)
       where
-        (pname, baseSpec) = case nameAndSpec of
+        (pname, baseSpec) = case specAndName of
-          (Just pname', (_, spec)) -> (pname', PackageSpec spec)
+          (Just (_, spec), Just pname') -> (pname', PackageSpec spec)
-          (Nothing, (pname', spec)) -> (pname', PackageSpec spec)
+          (Just (pname', spec), Nothing) -> (pname', PackageSpec spec)
+          (Nothing, Just pname') -> (pname', PackageSpec HMS.empty)
+          (Nothing, Nothing) -> (PackageName "unnamed", PackageSpec HMS.empty)
+    parseNameAndShortcut =
+      (,) <$>
+        Opts.optional (Opts.argument
+          (Opts.maybeReader (parseCmdShortcut cmd . T.pack))
+          (Opts.metavar "PACKAGE")) <*>
+        optName
     optName = Opts.optional $ PackageName <$> Opts.strOption
       ( Opts.long "name" <>
         Opts.short 'n' <>

src/Niv/Cmd.hs

@@ -11,8 +11,7 @@ import qualified Options.Applicative as Opts
 -- TODO: add filter
 data Cmd = Cmd
   { description :: forall a. Opts.InfoMod a
-  -- TODO: should be "Maybe"
+  , parseCmdShortcut :: T.Text -> Maybe (PackageName, Aeson.Object)
-  , parseShortcut :: T.Text -> (PackageName, Aeson.Object)
   , parsePackageSpec :: Opts.Parser PackageSpec
   , updateCmd :: Update () ()
   , name :: T.Text

src/Niv/Git/Cmd.hs

@@ -4,20 +4,27 @@ module Niv.Git.Cmd (gitCmd) where
 
 import Niv.Cmd
 import qualified Options.Applicative as Opts
+import qualified Options.Applicative.Help.Pretty as Opts
 
 gitCmd :: Cmd
 gitCmd = Cmd
   { description = describeGit
-  , parseShortcut = error "no parse for git"
+  , parseCmdShortcut = pure Nothing
   , parsePackageSpec = pure mempty
-  , updateCmd = undefined
+  , updateCmd = error "git update is not implemented yet"
   , name = "git"
   }
 
 describeGit :: Opts.InfoMod a
 describeGit = mconcat
   [ Opts.fullDesc
-  , Opts.progDesc "Echo a message back"
+  , Opts.progDesc "Add a git dependency. Experimental."
+  , Opts.headerDoc $ Just $
+      "Examples:" Opts.<$$>
+      "" Opts.<$$>
+      "  niv add git@github.com:stedolan/jq" Opts.<$$>
+      "  niv add ssh://git@github.com/stedolan/jq" Opts.<$$>
+      "  niv add https://github.com/stedolan/jq.git"
   ]
 
 -- for git:

src/Niv/GitHub/Cmd.hs

@@ -30,7 +30,7 @@ import qualified Options.Applicative.Help.Pretty as Opts
 githubCmd :: Cmd
 githubCmd = Cmd
   { description = describeGitHub
-  , parseShortcut = parseAddShortcutGitHub
+  , parseCmdShortcut = parseAddShortcutGitHub
   , parsePackageSpec = parseGitHubPackageSpec
   , updateCmd = githubUpdate'
   , name = "github"
@@ -104,7 +104,7 @@ parseGitHubPackageSpec =
 describeGitHub :: Opts.InfoMod a
 describeGitHub = mconcat
   [ Opts.fullDesc
-  , Opts.progDesc "Add dependency"
+  , Opts.progDesc "Add a GitHub dependency"
   , Opts.headerDoc $ Just $
       "Examples:" Opts.<$$>
       "" Opts.<$$>
@@ -114,17 +114,19 @@ describeGitHub = mconcat
   ]
 
 -- parse a github shortcut of the form "owner/repo"
-parseAddShortcutGitHub :: T.Text -> (PackageName, Aeson.Object)
+parseAddShortcutGitHub :: T.Text -> Maybe (PackageName, Aeson.Object)
-parseAddShortcutGitHub str = -- Opts.strArgument (Opts.metavar "PACKAGE") <&>
+parseAddShortcutGitHub str =
       -- parses a string "owner/repo" into package name (repo) and spec (owner +
       -- repo)
         case T.span (/= '/') str of
           (owner@(T.null -> False)
-            , T.uncons -> Just ('/', repo@(T.null -> False))) ->
+            , T.uncons -> Just ('/', repo@(T.null -> False))) -> Just
               ( PackageName repo
               , HMS.fromList [ "owner" .= owner, "repo" .= repo ])
-          _ -> (PackageName str, HMS.empty)
+          -- XXX: this should be "Nothing" but for the time being we keep
-
+          -- backwards compatibility with "niv add foo" adding "foo" as a
+          -- package name.
+          _ -> Just (PackageName str, HMS.empty)
 
 -- | The IO (real) github update
 githubUpdate' :: Update () ()