Fix finding missing paths

Closes GH-51.
Closes GH-52.

Author: wooorm

lib/finder.js

@@ -105,9 +105,10 @@ function expand(input, options, next) {
         paths.push(file)
       }
     } else {
+      const fp = file.path ? path.relative(options.cwd, file.path) : options.cwd
       file.cwd = options.cwd
-      file.path = path.relative(options.cwd, file.path)
-      file.history = [file.path]
+      file.path = fp
+      file.history = [fp]
       paths.push(file)
     }
   }

test/input.js

@@ -11,7 +11,7 @@ import {engine} from '../index.js'
 const fixtures = path.join('test', 'fixtures')
 
 test('input', (t) => {
-  t.plan(19)
+  t.plan(20)
 
   t.test('should fail without input', (t) => {
     const stream = new PassThrough()
@@ -364,7 +364,7 @@ test('input', (t) => {
     )
   })
 
-  t.test('should not atempt to read files with `value` (1)', (t) => {
+  t.test('should not attempt to read files with `value` (1)', (t) => {
     const stderr = spy()
     const cwd = path.join(fixtures, 'ignore-file')
     const file = toVFile({
@@ -400,7 +400,7 @@ test('input', (t) => {
     )
   })
 
-  t.test('should not atempt to read files with `value` (2)', (t) => {
+  t.test('should not attempt to read files with `value` (2)', (t) => {
     const stderr = spy()
     const cwd = path.join(fixtures, 'ignore-file')
     const file = toVFile({
@@ -428,6 +428,33 @@ test('input', (t) => {
     )
   })
 
+  t.test('should not attempt to read files with `value` (3)', (t) => {
+    const stderr = spy()
+    const cwd = path.join(fixtures, 'empty')
+    const file = toVFile({value: 'foo'})
+
+    t.plan(1)
+
+    engine(
+      {processor: noop, cwd, streamError: stderr.stream, files: [file]},
+      (error, code) => {
+        t.deepEqual(
+          [error, code, stderr()],
+          [
+            null,
+            0,
+            'test' +
+              path.sep +
+              'fixtures' +
+              path.sep +
+              'empty: no issues found\n'
+          ],
+          'should report'
+        )
+      }
+    )
+  })
+
   t.test('should include given ignored files (#2)', (t) => {
     const stderr = spy()