test: add parse-examples script

.gitignore

@@ -6,3 +6,5 @@ build
 node_modules
 package-lock.json
 target
+
+examples/luvit

examples/init.lua

@@ -0,0 +1,3 @@
+#!/usr/bin/env lua
+
+return 42

lua/package.json

@@ -27,7 +27,8 @@
   "scripts": {
     "build": "tree-sitter generate",
     "postbuild": "node-gyp build",
-    "test": "tree-sitter test"
+    "test": "tree-sitter test",
+    "posttest": "../script/parse-examples lua"
   },
   "dependencies": {
     "nan": "^2.14.2"

script/parse-examples

@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+cd "$(dirname "${0}")/.."
+
+declare language="all"
+
+if test -n "${1}"; then
+  language="${1}";
+  shift;
+fi
+
+checkout_repo() {
+  local -r path="${1}"
+  local -r repo="${2}"
+  local -r sha="${3}"
+
+  echo "Checking out github.com/${repo}#${sha} in ${path}"
+
+  mkdir -p "${path}"
+  pushd "${path}" >/dev/null
+
+  if [[ ! -d ".git" ]]; then
+    git init --quiet
+    git remote add origin "https://github.com/${repo}.git"
+    git fetch --quiet --depth 1 origin "${sha}"
+  elif [[ "${sha}" != "$(git rev-parse HEAD)" ]]; then
+    git fetch --quiet --depth 1 origin "${sha}"
+  fi
+
+  git checkout --quiet FETCH_HEAD
+
+  popd >/dev/null
+
+  echo
+}
+
+checkout_repo "./examples/luvit" "luvit/luvit" "9841bc17aaab32fa63e11063cf68f82da615eefd"
+
+lua_parse_examples() {
+  local -r known_failures="$(cat script/known_failures.txt)"
+
+  pushd "./lua" >/dev/null
+
+  tree-sitter parse --quiet \
+    "../examples/luvit/**/*.lua" \
+    $(for file in ${known_failures}; do echo "!${file}"; done)
+
+  declare -r example_count=$(find ../examples -name "*.lua" | wc -l)
+  declare -r failure_count=$(wc -w <<< "${known_failures}")
+  declare -r success_count=$(( ${example_count} - ${failure_count} ))
+  declare -r success_percent=$(bc -l <<< "100*${success_count}/${example_count}")
+
+  printf \
+    "[Lua] Successfully parsed %d of %d example files (%.1f%%)\n" \
+    ${success_count} ${example_count} ${success_percent}
+
+  popd >/dev/null
+}
+
+case "${language}" in
+  lua) lua_parse_examples;;
+  all)
+    lua_parse_examples
+    ;;
+esac