fix: issue #16 - Throw error on resolving non-root path (#43)

BREAKING CHANGE: non-root paths throw an error

Prior to this change a call to the resolver with a path like this:

    resolver.resolve(blob, '/a/b/c/d')

would just return the `blob` and an empty remainder path.

With this commit, it will throw an Error as there is no such path.

package.json

@@ -32,7 +32,8 @@
     "greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>",
     "greenkeeper[bot] <greenkeeper[bot]@users.noreply.github.com>",
     "kumavis <aaron@kumavis.me>",
-    "kumavis <kumavis@users.noreply.github.com>"
+    "kumavis <kumavis@users.noreply.github.com>",
+    "Chris Hafey <chafey@gmail.com>"
   ],
   "license": "MIT",
   "bugs": {

src/index.js

@@ -14,12 +14,16 @@ module.exports = {
      * Always returns the raw data as value without any remainderPath.
      *
      * @param {Buffer} binaryBlob - Binary representation of a PB block
-     * @param {string} [path='/'] - Path that should be resolved (that value is ignored)
+     * @param {string} [path='/'] - Path that should be resolved.  Must be '/' or an exception is thrown
      * @returns {Object} result - Result of the path it it was resolved successfully
      * @returns {*} result.value - The raw data
      * @returns {string} result.remainderPath - An empty string
      */
     resolve: (binaryBlob, path) => {
+      if (path !== '/') {
+        throw new Error('Only the root path / may be resolved')
+      }
+
       return {
         value: binaryBlob,
         remainderPath: ''

test/index.spec.js

@@ -23,11 +23,17 @@ describe('raw codec', () => {
   })
 
   it('resolver.resolve', () => {
-    const result = resolver.resolve(testBlob, 'a/b/c/d')
+    const result = resolver.resolve(testBlob, '/')
     expect(result.value.toString('hex')).to.equal(testData.toString('hex'))
     expect(result.remainderPath).to.equal('')
   })
 
+  it('resolver.resolve throws on non-root path', () => {
+    expect(() => resolver.resolve(testBlob, 'a/b/c/d')).to.throw(
+      'Only the root path / may be resolved'
+    )
+  })
+
   it('resolver.tree', () => {
     const paths = resolver.tree(testBlob)
     expect(paths.value).to.be.undefined()