Decouple testing with Nix

Use Nix for build isolation not for test running.

19 files changed, 415 insertions, 267 deletions

diff --git a/.build.yml b/.build.yml
index 2dce81d..ed27fd4 100644
--- a/.build.yml
+++ b/.build.yml
@@ -19,5 +19,4 @@ tasks:
   - docs: |
       cd website/
       nix-build -A publishScript
-      source ./scripts/publish-env.sh
       ./result/bin/publish.sh
diff --git a/a-propos.md b/a-propos.md
index 661f25e..689da32 100644
--- a/a-propos.md
+++ b/a-propos.md
@@ -29,4 +29,4 @@ regrouper-les en utilisant LaTeX dans recueils de chansons.
 
 [Liste de pastebins]({% link pastebins.fr.md %}).
 
-[Articles par catégory]({% link categories.fr.md %}).
+[Articles par catégorie]({% link categories.fr.md %}).
diff --git a/default.nix b/default.nix
index b0cb35c..60e879b 100644
--- a/default.nix
+++ b/default.nix
@@ -1,114 +1,60 @@
 let
-  pkgs = import (fetchTarball
-    "https://github.com/NixOS/nixpkgs/archive/nixos-unstable.tar.gz") { };
-  dicts = rec {
-    mkDict = let
-      prefix =
-        "https://raw.githubusercontent.com/wooorm/dictionaries/61016e00e276f9bf5e52cbc6c02a45f2e49b2c7e/dictionaries";
-    in { lang, dicSHA256, affSHA256 }:
-    let
-      dic = builtins.fetchurl {
-        url = "${prefix}/${lang}/index.dic";
-        sha256 = dicSHA256;
-      };
-      aff = builtins.fetchurl {
-        url = "${prefix}/${lang}/index.aff";
-        sha256 = affSHA256;
-      };
-    in pkgs.stdenv.mkDerivation {
-      name = "songbooks-dict-${lang}";
-      builder = builtins.toFile "builder.sh" ''
-        source $stdenv/setup
-        install -dm755 $out/share/hunspell
-        install -m644 ${dic} $out/share/hunspell/${lang}.dic
-        install -m644 ${aff} $out/share/hunspell/${lang}.aff
-        runHook postInstall
-      '';
-    };
-    en = mkDict {
-      lang = "en";
-      dicSHA256 = "1k4660ccwwpwac0rc7b8ih3vd24kxgvljkrakv2l1f72yfpw3bp2";
-      affSHA256 = "0yvc2fhc03y0y1gwjyb20ifcrxnzm3ama1fri9r5gna092fz3qca";
-    };
-    pt = mkDict {
-      lang = "pt";
-      dicSHA256 = "1z0kfxv8m361xhp4zwdlsn2ib8q3rnljj0b2s4482alyxpd00h9x";
-      affSHA256 = "1ssj1g7qwh0lv3ajzvchwsfr7cgzrlqms28m1j3gm1y2avi50qhw";
-    };
-    fr = mkDict {
-      lang = "fr";
-      dicSHA256 = "10p6jlk9j117mjd1z3dp3vfszcvxqha11kfvksqhvrq4ld9xwzbn";
-      affSHA256 = "0d6k608h7gm1za3vdq1fhlwqzz2zxg1z0bx1bfvi0spg4a2mn09p";
-    };
-  };
-  myHunspell = (pkgs.hunspellWithDicts (with dicts; [ en pt fr ]));
-in rec {
-  utils = import ./utils.nix {
-    pkgs = pkgs;
-    src = pkgs.nix-gitignore.gitignoreSource [ ] ./.;
-    baseName = "website";
-  };
+  niv-sources = import ./nix/sources.nix;
+  pkgs = import niv-sources.nixpkgs { };
+  src = pkgs.nix-gitignore.gitignoreSource [ "!.git" ] ./.;
+  utils-i18n = pkgs.callPackage ./utils-i18n.nix { };
+
   jekyllEnv = pkgs.bundlerEnv {
     name = "jekyll-env";
     gemfile = ./Gemfile;
     lockfile = ./Gemfile.lock;
     gemset = ./gemset.nix;
   };
-  subtasks = rec {
-    hunspellCheck = utils.baseTask.overrideAttrs (baseAttrs: {
-      name = "${baseAttrs.name}-hunspell";
-      buildInputs = baseAttrs.buildInputs ++ [ myHunspell ];
-      buildPhase = ''
-        patchShebangs .
-        ./spelling/check-spelling.sh "${subtasks.docs}"
-        touch $out
-      '';
-    });
-    assertContent = utils.baseTask.overrideAttrs (baseAttrs: {
-      name = "${baseAttrs.name}-assert-content";
-      buildInputs = baseAttrs.buildInputs ++ [ pkgs.jq ];
-      buildPhase = ''
-        patchShebangs .
-        ./scripts/assert-content.sh "${subtasks.docs}/site.json"
-        touch $out
-      '';
-    });
-    docs = utils.baseTask.overrideAttrs (baseAttrs: {
-      name = "${baseAttrs.name}-docs";
-      buildInputs = [ jekyllEnv ];
-      buildPhase = ''
-        patchShebangs .
-        jekyll build -d $out
-      '';
-    });
-  };
-  test = utils.test [
-    utils.formatNix
-    (utils.shellcheck null)
-    (utils.fixme [
-      "utils.nix"
-      "TODOs.org"
-      "_pastebins/"
-      "_posts/"
-      "_tils/"
-      "drafts/"
-      "templates/"
-    ])
-    subtasks.hunspellCheck
-    subtasks.assertContent
-    subtasks.docs
+  projectBuildInputs = with pkgs; [
+    jekyllEnv
+
+    nixfmt
+    git
+    shellcheck
+    jq
+    niv
+    (hunspellWithDicts (with utils-i18n.dicts; [ en pt fr ]))
   ];
-  shell = pkgs.mkShell rec {
-    name = "website-shell";
-    buildInputs = [ jekyllEnv myHunspell ];
+in rec {
+  site = pkgs.stdenv.mkDerivation {
+    inherit src;
+    name = "website-site";
+    phases = [ "unpackPhase" "buildPhase" ];
+    buildInputs = [ jekyllEnv ];
+    buildPhase = ''
+      patchShebangs .
+      jekyll build -d $out
+    '';
   };
-  publishScript = utils.overwritingPublishScript {
-    docsDerivation = subtasks.docs;
-    overwrite = true;
+  test = pkgs.stdenv.mkDerivation {
+    inherit src;
+    name = "website-test";
+    phases = [ "unpackPhase" "buildPhase" ];
+    buildInputs = projectBuildInputs;
+    buildPhase = ''
+      patchShebangs .
+      ./tests.sh
+      touch $out
+    '';
   };
-  fastPublishScript = utils.overwritingPublishScript {
-    docsDerivation = subtasks.docs;
-    overwrite = false;
+  shell = pkgs.mkShell rec {
+    name = "website-shell";
+    buildInputs = projectBuildInputs;
   };
-  site = subtasks.docs;
+  publishScript = pkgs.writeShellScriptBin "publish.sh" ''
+    set -euo pipefail
+    SERVER_URL='root@euandre.org'
+    REMOTE_PATH='/home/user-data/www/default/'
+    OUT_DOCS='${site}'
+    ${pkgs.openssh}/bin/ssh -o StrictHostKeyChecking=no "$SERVER_URL" rm -rf "$REMOTE_PATH/*"
+    ${pkgs.rsync}/bin/rsync -avzP                                   \
+                            --rsh="ssh -o StrictHostKeyChecking=no" \
+                            "$OUT_DOCS/"                            \
+                            "$SERVER_URL:$REMOTE_PATH"
+  '';
 }
diff --git a/nix/sources.json b/nix/sources.json
new file mode 100644
index 0000000..c8fe824
--- /dev/null
+++ b/nix/sources.json
@@ -0,0 +1,26 @@
+{
+    "niv": {
+        "branch": "master",
+        "description": "Easy dependency management for Nix projects",
+        "homepage": "https://github.com/nmattia/niv",
+        "owner": "nmattia",
+        "repo": "niv",
+        "rev": "9d35b9e4837ab88517210b1701127612c260eccf",
+        "sha256": "0q50xhnm8g2yfyakrh0nly4swyygxpi0a8cb9gp65wcakcgvzvdh",
+        "type": "tarball",
+        "url": "https://github.com/nmattia/niv/archive/9d35b9e4837ab88517210b1701127612c260eccf.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
+    "nixpkgs": {
+        "branch": "nixos-unstable",
+        "description": "Nix Packages collection",
+        "homepage": "",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "420f89ceb267b461eed5d025b6c3c0e57703cc5c",
+        "sha256": "0c9kr76p6nmf4z2j2afgcddckbaxq6kxlmp1895h6qamm1c0ypb9",
+        "type": "tarball",
+        "url": "https://github.com/NixOS/nixpkgs/archive/420f89ceb267b461eed5d025b6c3c0e57703cc5c.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    }
+}
diff --git a/nix/sources.nix b/nix/sources.nix
new file mode 100644
index 0000000..9f418ad
--- /dev/null
+++ b/nix/sources.nix
@@ -0,0 +1,197 @@
+# This file has been generated by Niv.
+
+let
+
+  #
+  # The fetchers. fetch_<type> fetches specs of type <type>.
+  #
+
+  fetch_file = pkgs: name: spec:
+    let name' = sanitizeName name + "-src";
+    in if spec.builtin or true then
+      builtins_fetchurl {
+        inherit (spec) url sha256;
+        name = name';
+      }
+    else
+      pkgs.fetchurl {
+        inherit (spec) url sha256;
+        name = name';
+      };
+
+  fetch_tarball = pkgs: name: spec:
+    let name' = sanitizeName name + "-src";
+    in if spec.builtin or true then
+      builtins_fetchTarball {
+        name = name';
+        inherit (spec) url sha256;
+      }
+    else
+      pkgs.fetchzip {
+        name = name';
+        inherit (spec) url sha256;
+      };
+
+  fetch_git = name: spec:
+    let
+      ref = if spec ? ref then
+        spec.ref
+      else if spec ? branch then
+        "refs/heads/${spec.branch}"
+      else if spec ? tag then
+        "refs/tags/${spec.tag}"
+      else
+        abort
+        "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
+    in builtins.fetchGit {
+      url = spec.repo;
+      inherit (spec) rev;
+      inherit ref;
+    };
+
+  fetch_local = spec: spec.path;
+
+  fetch_builtin-tarball = name:
+    throw ''
+      [${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.
+              $ niv modify ${name} -a type=tarball -a builtin=true'';
+
+  fetch_builtin-url = name:
+    throw ''
+      [${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.
+              $ niv modify ${name} -a type=file -a builtin=true'';
+
+  #
+  # Various helpers
+  #
+
+  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
+  sanitizeName = name:
+    (concatMapStrings (s: if builtins.isList s then "-" else s)
+      (builtins.split "[^[:alnum:]+._?=-]+"
+        ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)));
+
+  # The set of packages used when specs are fetched using non-builtins.
+  mkPkgs = sources: system:
+    let
+      sourcesNixpkgs = import
+        (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) {
+          inherit system;
+        };
+      hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
+      hasThisAsNixpkgsPath = <nixpkgs> == ./.;
+    in if builtins.hasAttr "nixpkgs" sources then
+      sourcesNixpkgs
+    else if hasNixpkgsPath && !hasThisAsNixpkgsPath then
+      import <nixpkgs> { }
+    else
+      abort ''
+        Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
+        add a package called "nixpkgs" to your sources.json.
+      '';
+
+  # The actual fetching function.
+  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 pkgs name spec
+    else if spec.type == "tarball" then
+      fetch_tarball pkgs name spec
+    else if spec.type == "git" then
+      fetch_git name spec
+    else if spec.type == "local" then
+      fetch_local spec
+    else if spec.type == "builtin-tarball" then
+      fetch_builtin-tarball name
+    else if spec.type == "builtin-url" then
+      fetch_builtin-url name
+    else
+      abort
+      "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";
+
+  # If the environment variable NIV_OVERRIDE_${name} is set, then use
+  # the path directly as opposed to the fetched source.
+  replace = name: drv:
+    let
+      saneName = stringAsChars
+        (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
+      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
+    in if ersatz == "" then drv else ersatz;
+
+  # Ports of functions for older nix versions
+
+  # a Nix version of mapAttrs if the built-in doesn't exist
+  mapAttrs = builtins.mapAttrs or (f: set:
+    with builtins;
+    listToAttrs (map (attr: {
+      name = attr;
+      value = f attr set.${attr};
+    }) (attrNames set)));
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
+  range = first: last:
+    if first > last then
+      [ ]
+    else
+      builtins.genList (n: first + n) (last - first + 1);
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
+  stringToCharacters = s:
+    map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
+  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
+  concatMapStrings = f: list: concatStrings (map f list);
+  concatStrings = builtins.concatStringsSep "";
+
+  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
+  optionalAttrs = cond: as: if cond then as else { };
+
+  # fetchTarball version that is compatible between all the versions of Nix
+  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
+    let inherit (builtins) lessThan nixVersion fetchTarball;
+    in if lessThan nixVersion "1.12" then
+      fetchTarball
+      ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
+    else
+      fetchTarball attrs;
+
+  # fetchurl version that is compatible between all the versions of Nix
+  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
+    let inherit (builtins) lessThan nixVersion fetchurl;
+    in if lessThan nixVersion "1.12" then
+      fetchurl
+      ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
+    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 = replace name (fetch config.pkgs name spec); })
+    config.sources;
+
+  # The "config" used by the fetchers
+  mkConfig = { sourcesFile ?
+      if builtins.pathExists ./sources.json then ./sources.json else null
+    , sources ? if isNull sourcesFile then
+      { }
+    else
+      builtins.fromJSON (builtins.readFile sourcesFile)
+    , system ? builtins.currentSystem, pkgs ? mkPkgs sources system }: rec {
+      # The sources, i.e. the attribute set of spec name to spec
+      inherit sources;
+
+      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
+      inherit pkgs;
+    };
+
+in mkSources (mkConfig { }) // {
+  __functor = _: settings: mkSources (mkConfig settings);
+}
diff --git a/scripts/assert-content.sh b/scripts/assert-content.sh
index a0d661f..e694580 100755
--- a/scripts/assert-content.sh
+++ b/scripts/assert-content.sh
@@ -8,23 +8,8 @@ red() { echo -e "${red}${1}${end}"; }
 
 ## Constant definitions
 
-JSON="${1:-}"
-[[ -z "${JSON}" ]] && {
-  red 'Missing input JSON file.'
-  cat <<EOF
-Usage:
-    $0 <SITE_JSON_PATH>
-
-      Arguments
-        SITE_JSON_PATH     Path to the site.json file which contains data and metadata about pages of the site.
-
-Examples:
-    $0 _site/site.json
-    $0 result/site.json
-    $0 \$(nix-build -A subtasks.docs)/site.json
-EOF
-  exit 2
-}
+jekyll build
+JSON='_site/site.json'
 
 LANGS=(en pt fr)
 IGNORED_PAGES=(site.json sitemap.xml *.atom)
@@ -138,6 +123,11 @@ for til in $(jq -r '.tils[] | @base64' "${JSON}"); do
   assert-frontmatter "$til" 'post' '_tils'
 done
 
+echo Linting slides... >&2
+for slide in $(jq -r '.slides[] | @base64' "${JSON}"); do
+  assert-frontmatter "$slide" 'post' '_slides'
+done
+
 echo Asserting unique refs... >&2
 KNOWN_IDS=()
 assert-unique-ref() {
@@ -163,5 +153,6 @@ assert-unique-ref() {
 assert-unique-ref "$(jq -r    '.pages[] | @base64' "${JSON}")"
 assert-unique-ref "$(jq -r '.articles[] | @base64' "${JSON}")"
 assert-unique-ref "$(jq -r     '.tils[] | @base64' "${JSON}")"
+assert-unique-ref "$(jq -r   '.slides[] | @base64' "${JSON}")"
 
 echo Done. >&2
diff --git a/scripts/assert-nixfmt.sh b/scripts/assert-nixfmt.sh
new file mode 100755
index 0000000..7a68fa9
--- /dev/null
+++ b/scripts/assert-nixfmt.sh
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+cd "$(dirname "${BASH_SOURCE[0]}")"
+cd ../
+
+format() {
+  nix_file="${1}"
+  diff <(nixfmt < "${nix_file}") "${nix_file}" || {
+    echo "The file '${nix_file}' is unformatted. To fix it, run:"
+    echo "  nixfmt ${nix_file}"
+    exit 1
+  }
+}
+export -f format
+
+find . -type f -name '*.nix' -print0 | xargs -0 -I% bash -c "format %"
diff --git a/scripts/assert-shellcheck.sh b/scripts/assert-shellcheck.sh
new file mode 100755
index 0000000..e24c29c
--- /dev/null
+++ b/scripts/assert-shellcheck.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+cd "$(dirname "${BASH_SOURCE[0]}")"
+cd ../
+
+git ls-files | grep '\.sh$' | xargs shellcheck
diff --git a/scripts/assert-spelling.sh b/scripts/assert-spelling.sh
new file mode 100755
index 0000000..caaecfa
--- /dev/null
+++ b/scripts/assert-spelling.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+cd "$(dirname "${BASH_SOURCE[0]}")"
+cd ../
+
+export LANG=C.UTF-8
+
+for DICT in scripts/spelling/*.txt; do
+  diff <(sort "$DICT") "$DICT" || {
+    echo "The $DICT dictionary is unsorted. To fix it, run:" >&2
+    echo "  LANG=C.UTF-8 sort docs/$DICT | sponge docs/$DICT" >&2
+    exit 1
+  }
+done
+
+OUT="$(mktemp)"
+shopt -s globstar
+jekyll build
+for f in _site/**/*.html; do
+  if ! grep -E '^_site/pastebin' <(echo "$f") > /dev/null; then
+    if ! grep -E '^_site/vendor/' <(echo "$f") > /dev/null; then
+      l="$(head -n2 "$f" | tail -n1 | cut -d\" -f2)"
+      hunspell -u3 -H -d "$l" -p <(cat scripts/spelling/international.txt "scripts/spelling/$l.txt") "$f" | tee -a "$OUT"
+    fi
+  fi
+done
+
+if [[ -s "$OUT" ]]; then
+  printf "\nvvv Mispelled words detected by hunspell.\n\n"
+  sort < "$OUT" | uniq
+  printf "\n^^^\n" >&2
+  exit 1
+else
+  echo "No spelling errors detected"
+  exit 0
+fi
diff --git a/scripts/assert-todos.sh b/scripts/assert-todos.sh
new file mode 100755
index 0000000..a59b4cd
--- /dev/null
+++ b/scripts/assert-todos.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+cd "$(dirname "${BASH_SOURCE[0]}")"
+cd ../
+
+# shellcheck disable=2046
+if grep -R FIXME $(git ls-files) | \
+    grep -Ev '^(vendor/|.git/|scripts/assert-todos.sh|templates)'; then
+  echo "Found dangling FIXME markers on the project."
+  echo "You should write them down properly on TODOs.org."
+  exit 1
+fi
diff --git a/scripts/publish-env.sh b/scripts/publish-env.sh
deleted file mode 100644
index d5e8be2..0000000
--- a/scripts/publish-env.sh
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/usr/bin/env bash
-
-export SERVER_URL=root@euandre.org
-export DOCS_SERVER_PATH="/home/user-data/www/default/"
diff --git a/spelling/en.txt b/scripts/spelling/en.txt
index bebfc76..bebfc76 100644
--- a/spelling/en.txt
+++ b/scripts/spelling/en.txt
diff --git a/spelling/fr.txt b/scripts/spelling/fr.txt
index aa09184..aa09184 100644
--- a/spelling/fr.txt
+++ b/scripts/spelling/fr.txt
diff --git a/spelling/international.txt b/scripts/spelling/international.txt
index 3536249..3536249 100644
--- a/spelling/international.txt
+++ b/scripts/spelling/international.txt
diff --git a/spelling/pt.txt b/scripts/spelling/pt.txt
index 2befc17..65d4ac8 100644
--- a/spelling/pt.txt
+++ b/scripts/spelling/pt.txt
@@ -23,6 +23,7 @@ achar
 arquivo
 artigos
 buscar
+categoria
 chegar
 comece
 comentário
diff --git a/spelling/check-spelling.sh b/spelling/check-spelling.sh
deleted file mode 100755
index 3ddfd2a..0000000
--- a/spelling/check-spelling.sh
+++ /dev/null
@@ -1,37 +0,0 @@
-#!/usr/bin/env bash
-set -Eeuo pipefail
-
-HTML_DIR="${1:-}"
-[[ -z "${HTML_DIR}" ]] && {
-  echo 'Undefined input HTML_DIR.' >&2
-  exit 2
-}
-
-# Required by =sort= and =hunspell=
-export LANG=C.UTF-8
-
-for DICT in spelling/*.txt; do
-  diff <(sort "$DICT" | uniq) "$DICT" || {
-    echo "The $DICT dictionary is unsorted. To fix it, run:" >&2
-    echo "  LANG=C.UTF-8 sort $DICT | uniq | sponge $DICT" >&2
-    exit 1
-  }
-done
-
-rm -f spelling.txt
-shopt -s globstar
-for f in "${HTML_DIR}"/**/*.html; do
-  if ! grep -E '/pastebin(/|s.html)' <(echo "$f") > /dev/null; then
-    l="$(head -n2 "$f" | tail -n1 | cut -d\" -f2)"
-    hunspell -u3 -H -d "$l" -p <(cat spelling/international.txt "spelling/$l.txt") "$f" | tee -a spelling.txt
-  fi
-done
-
-if [[ -s spelling.txt ]]; then
-  printf "\nvvv Mispelled words detected by hunspell.\n\n" >&2
-  sort < spelling.txt | uniq >&2
-  printf "\n^^^\n" >&2
-  exit 1
-else
-  echo "No words mispelled" >&2
-fi
diff --git a/tests.sh b/tests.sh
new file mode 100755
index 0000000..46f1f0e
--- /dev/null
+++ b/tests.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+cd "$(dirname "${BASH_SOURCE[0]}")"
+
+set -x
+
+./scripts/assert-spelling.sh
+./scripts/assert-nixfmt.sh
+./scripts/assert-shellcheck.sh
+./scripts/assert-todos.sh
+
+./scripts/assert-content.sh
diff --git a/utils-i18n.nix b/utils-i18n.nix
new file mode 100644
index 0000000..379cd3b
--- /dev/null
+++ b/utils-i18n.nix
@@ -0,0 +1,52 @@
+{ pkgs }: rec {
+  sphinx-intl = with pkgs.python3.pkgs;
+    buildPythonPackage rec {
+      pname = "sphinx-intl";
+      version = "2.0.1";
+      src = fetchPypi {
+        inherit pname version;
+        sha256 = "1d1q0sanjp4nkfvhsxi75zf3xjyyi8nzxvl3v7l0jy9ld70nwnmj";
+      };
+      propagatedBuildInputs = with pkgs.python3Packages; [ Babel click sphinx ];
+    };
+  dicts = rec {
+    mkDict = let
+      prefix =
+        "https://raw.githubusercontent.com/wooorm/dictionaries/61016e00e276f9bf5e52cbc6c02a45f2e49b2c7e/dictionaries";
+    in { lang, dicSHA256, affSHA256 }:
+    let
+      dic = builtins.fetchurl {
+        url = "${prefix}/${lang}/index.dic";
+        sha256 = dicSHA256;
+      };
+      aff = builtins.fetchurl {
+        url = "${prefix}/${lang}/index.aff";
+        sha256 = affSHA256;
+      };
+    in pkgs.stdenv.mkDerivation {
+      name = "x-bindgen-dict-${lang}";
+      builder = builtins.toFile "builder.sh" ''
+        source $stdenv/setup
+        install -dm755 $out/share/hunspell
+        install -m644 ${dic} $out/share/hunspell/${lang}.dic
+        install -m644 ${aff} $out/share/hunspell/${lang}.aff
+        runHook postInstall
+      '';
+    };
+    en = mkDict {
+      lang = "en";
+      dicSHA256 = "1k4660ccwwpwac0rc7b8ih3vd24kxgvljkrakv2l1f72yfpw3bp2";
+      affSHA256 = "0yvc2fhc03y0y1gwjyb20ifcrxnzm3ama1fri9r5gna092fz3qca";
+    };
+    pt = mkDict {
+      lang = "pt";
+      dicSHA256 = "1z0kfxv8m361xhp4zwdlsn2ib8q3rnljj0b2s4482alyxpd00h9x";
+      affSHA256 = "1ssj1g7qwh0lv3ajzvchwsfr7cgzrlqms28m1j3gm1y2avi50qhw";
+    };
+    fr = mkDict {
+      lang = "fr";
+      dicSHA256 = "10p6jlk9j117mjd1z3dp3vfszcvxqha11kfvksqhvrq4ld9xwzbn";
+      affSHA256 = "0d6k608h7gm1za3vdq1fhlwqzz2zxg1z0bx1bfvi0spg4a2mn09p";
+    };
+  };
+}
diff --git a/utils.nix b/utils.nix
deleted file mode 100644
index 5bcbb10..0000000
--- a/utils.nix
+++ /dev/null
@@ -1,105 +0,0 @@
-{ pkgs, src, baseName }: rec {
-  baseTask = pkgs.stdenv.mkDerivation {
-    name = "${baseName}-task";
-    src = src;
-    buildInputs = [ ];
-    phases = "unpackPhase buildPhase";
-    buildPhase = ''
-      echo "ERROR: base task buildPhase not overriden."
-      exit 1
-    '';
-  };
-  shellcheck = ignoredFindPattern:
-    baseTask.overrideAttrs (baseAttrs: rec {
-      name = "${baseAttrs.name}-shellcheck";
-      buildInputs = baseAttrs.buildInputs ++ [ pkgs.shellcheck ];
-      ignoredPattern =
-        if ignoredFindPattern == null then "" else ignoredFindPattern;
-      buildPhase = ''
-        find . -type f \( -name '*.sh' -and -regextype egrep ! -regex '${ignoredPattern}' \) -print0 | xargs -0 shellcheck -x
-        touch $out
-      '';
-    });
-  formatNix = baseTask.overrideAttrs (baseAttrs: {
-    name = "${baseAttrs.name}-nixfmt";
-    buildInputs = baseAttrs.buildInputs ++ [ pkgs.nixfmt ];
-    buildPhase = ''
-      format() {
-        nix_file="$1"
-        diff <(nixfmt < "$nix_file") "$nix_file" || {
-          echo "The $nix_file is unformatted. To fix it, run:"
-          echo "  nixfmt $nix_file"
-          exit 1
-        }
-      }
-      export -f format
-      find . -type f -name '*.nix' -print0 | xargs -0 -I{} bash -c "format {}" \;
-      touch $out
-    '';
-  });
-  fixme = ignoredFiles:
-    baseTask.overrideAttrs (baseAttrs: rec {
-      name = "${baseAttrs.name}-fixme";
-      buildInputs = baseAttrs.buildInputs ++ [ pkgs.ag ];
-      ignoredPattern = pkgs.lib.fold (a: b: " --ignore ${a} ${b}") ""
-        (if ignoredFiles == null then [
-          "utils.nix"
-          "TODOs.org"
-        ] else
-          ignoredFiles);
-      buildPhase = ''
-        ag FIXME ${ignoredPattern} || {
-          touch $out
-          exit 0
-        }
-        echo "  Found dangling FIXME markers on the project."
-        echo "  You should write them down properly on TODOs.org."
-        exit 1
-      '';
-    });
-  readmeOrg = title:
-    baseTask.overrideAttrs (baseAttrs: {
-      name = "${baseAttrs.name}-readme-docs";
-      buildInputs = [ pkgs.pandoc ];
-      buildPhase = ''
-        pandoc README.org -o $out --css docs/README.css --to=html5 --self-contained --metadata title="${title}"
-      '';
-    });
-  test = testDerivations:
-    baseTask.overrideAttrs (baseAttrs: {
-      name = "${baseAttrs.name}-test";
-      buildPhase = ''
-        echo "Ran tests for:"
-        for d in ${builtins.toString testDerivations}; do
-          echo "  $d"
-        done
-        echo "All tests passed!"
-        touch $out
-      '';
-    });
-  shellEnvironmentBuild = shellBuildInputs:
-    baseTask.overrideAttrs (baseAttrs: {
-      name = "${baseAttrs.name}-shell-build-inputs";
-      buildPhase = ''
-        echo "Can build shell environment for shellBuildInputs!"
-        echo noop > $out
-      '';
-    });
-  shellEnvironment = shellBuildInputs:
-    pkgs.mkShell {
-      name = "${baseName}-shell";
-      buildInputs = shellBuildInputs;
-    };
-  overwritingPublishScript = { docsDerivation, overwrite ? true }:
-    pkgs.writeShellScriptBin "publish.sh" ''
-      set -euo pipefail
-      OUT_DOCS="${docsDerivation}"
-      ${
-        if overwrite then "" else "# "
-      }${pkgs.openssh}/bin/ssh -o StrictHostKeyChecking=no "$SERVER_URL" rm -rf "$DOCS_SERVER_PATH/*"
-      ${pkgs.rsync}/bin/rsync -avzP                                   \
-                              --rsh="ssh -o StrictHostKeyChecking=no" \
-                              "$OUT_DOCS/"                            \
-                              "$SERVER_URL:$DOCS_SERVER_PATH"
-    '';
-}