feat: read config, read history, hash files

most of the functionality exists now

src/utils.js

@@ -0,0 +1,64 @@
+const path = require('path');
+const fs = require('fs');
+const os = require('os');
+const JoyCon = require('joycon');
+
+exports.getRootPath = () => process.cwd();
+
+exports.getHomeDir = () => os.homedir();
+
+exports.getDataDir = () => path.join(exports.getHomeDir(), '.local/share');
+
+exports.canAccessFile = (p, flag) => {
+  try {
+    fs.accessSync(p, flag || fs.constants.R_OK);
+    return true;
+  } catch (e) {
+    return false;
+  }
+};
+
+exports.getFileContents = (filePath, opts = {}) => {
+  if (!exports.canAccessFile(filePath)) throw new Error(`File not found: ${filePath}`);
+
+  const content = fs.readFileSync(filePath);
+  if (opts.format === 'json') return JSON.parse(content);
+  if (opts.format === 'text') return content.toString();
+  return content;
+};
+
+exports.getRootFileContents = (filename, opts = {}) => {
+  return exports.getFileContents(path.join(exports.getRootPath(), filename), opts);
+};
+
+exports.getIdent = () => {
+  const { name } = exports.getRootFileContents('package.json', { format: 'json' });
+  return name;
+};
+
+exports.getBranch = () => {
+  const headPath = path.join(exports.getRootPath(), '.git/HEAD');
+  if (!exports.canAccessFile(headPath)) throw new Error(`Git HEAD not found: ${headPath}`);
+
+  const head = fs.readFileSync(headPath);
+  const match = /ref: refs\/heads\/([^\n]+)/.exec(head);
+  if (!match) throw new Error(`Unable to read branch from ${headPath}`);
+  return match[1];
+};
+
+exports.getConfig = (overrides = {}) => {
+  const joycon = new JoyCon();
+  const defaults = {
+    checkFiles: ['package-lock.json', 'yarn.lock'],
+    rootDir: process.cwd(),
+    dataDir: exports.getDataDir(),
+    cmd: 'npm',
+  };
+
+  const result = joycon.loadSync({
+    packageKey: 'pkgcomp',
+    files: ['.config/pkgcomp.json', 'pkgcomp.json', 'package.json'],
+  });
+
+  return Object.assign(defaults, result.data, overrides);
+};