Allow custom location for nix/sources.json

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## [0.2.7] 2019-12-08
+## Added
+* Support for custom path `sources.json` with `--sources-json`
+
 ## [0.2.6] 2019-12-05
 ## Changed
 * Fix `niv update` with `git` specs

README.md

@@ -199,11 +199,12 @@ $ niv update ghc -v 8.6.2
 ```
 niv - dependency manager for Nix projects
 
-version: 0.2.6
+version: 0.2.7
 
-Usage: niv COMMAND
+Usage: niv [-s|--sources-json FILE] COMMAND
 
 Available options:
+  -s,--sources-json FILE   Use FILE instead of nix/sources.json
   -h,--help                Show this help text
 
 Available commands:

nix/sources.nix

@@ -6,13 +6,13 @@ let
   # The fetchers. fetch_<type> fetches specs of type <type>.
   #
 
-  fetch_file = spec:
+  fetch_file = pkgs: spec:
     if spec.builtin or true then
       builtins_fetchurl { inherit (spec) url sha256; }
     else
       pkgs.fetchurl { inherit (spec) url sha256; };
 
-  fetch_tarball = spec:
+  fetch_tarball = pkgs: spec:
     if spec.builtin or true then
       builtins_fetchTarball { inherit (spec) url sha256; }
     else
@@ -43,27 +43,21 @@ let
       ''
       (builtins_fetchurl { inherit (spec) url sha256; });
 
-  #
-  # The sources to fetch.
-  #
-
-  sources = builtins.fromJSON (builtins.readFile ./sources.json);
-
   #
   # Various helpers
   #
 
   # The set of packages used when specs are fetched using non-builtins.
-  pkgs =
+  mkPkgs = sources:
     if hasNixpkgsPath
     then
       if hasThisAsNixpkgsPath
-      then import (builtins_fetchTarball { inherit (sources_nixpkgs) url sha256; }) {}
+      then import (builtins_fetchTarball { inherit (mkNixpkgs sources) url sha256; }) {}
       else import <nixpkgs> {}
     else
-      import (builtins_fetchTarball { inherit (sources_nixpkgs) url sha256; }) {};
+      import (builtins_fetchTarball { inherit (mkNixpkgs sources) url sha256; }) {};
 
-  sources_nixpkgs =
+  mkNixpkgs = sources:
     if builtins.hasAttr "nixpkgs" sources
     then sources.nixpkgs
     else abort
@@ -77,12 +71,12 @@ let
     (builtins.tryEval <nixpkgs>).success && <nixpkgs> == ./.;
 
   # The actual fetching function.
-  fetch = name: spec:
+  fetch = pkgs: name: spec:
 
     if ! builtins.hasAttr "type" spec then
       abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then fetch_file spec
-    else if spec.type == "tarball" then fetch_tarball spec
+    else if spec.type == "file" then fetch_file pkgs spec
+    else if spec.type == "tarball" then fetch_tarball pkgs spec
     else if spec.type == "git" then fetch_git spec
     else if spec.type == "builtin-tarball" then fetch_builtin-tarball spec
     else if spec.type == "builtin-url" then fetch_builtin-url spec
@@ -117,12 +111,26 @@ let
       else
         fetchurl attrs;
 
+  # Create the final "sources" from the config
+  mkSources = config:
+    mapAttrs (
+      name: spec:
+        if builtins.hasAttr "outPath" spec
+        then abort
+          "The values in sources.json should not have an 'outPath' attribute"
+        else
+          spec // { outPath = fetch config.pkgs name spec; }
+    ) config.sources;
+
+  # The "config" used by the fetchers
+  mkConfig =
+    { sourcesFile ? ./sources.json
+    }: rec {
+      # The sources, i.e. the attribute set of spec name to spec
+      sources = builtins.fromJSON (builtins.readFile sourcesFile);
+      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
+      pkgs = mkPkgs sources;
+    };
 in
-mapAttrs (
-  name: spec:
-    if builtins.hasAttr "outPath" spec
-    then abort
-      "The values in sources.json should not have an 'outPath' attribute"
-    else
-      spec // { outPath = fetch name spec; }
-) sources
+mkSources (mkConfig {}) //
+  { __functor = _: settings: mkSources (mkConfig settings); }

package.yaml

@@ -1,5 +1,5 @@
 name: niv
-version: 0.2.6
+version: 0.2.7
 license: MIT
 author: Nicolas Mattia <[email protected]>
 maintainer: Nicolas Mattia <[email protected]>

src/Data/Text/Extended.hs

@@ -3,14 +3,15 @@
 module Data.Text.Extended where
 
 import Niv.Logger
+import UnliftIO
 import System.Exit (exitFailure)
 import qualified Data.Text as T
 
 tshow :: Show a => a -> T.Text
 tshow = T.pack . show
 
 -- not quite the perfect place for this
-abort :: T.Text -> IO a
+abort :: MonadIO io => T.Text -> io a
 abort msg = do
     tsay $ T.unwords [ tbold $ tred "FATAL:", msg ]
-    exitFailure
+    liftIO exitFailure