better handle 'undefined' expected/actual

src/_make-diff.js

@@ -60,7 +60,7 @@ export default function ({ actual, expected }){
  else d.value.forEach(v => output.push(` ${JSON.stringify(v)},`))
  }
 
- output.unshift('[')
+ output.unshift('Array [')
  output.push(']')
 
  return output
@@ -81,6 +81,8 @@ export default function ({ actual, expected }){
  else output.push(d.value)
  }
 
+ output[0] = `Object ${output[0]}`
+
  return output.join('').split('\n')
  }
 

src/tap-arc.js

@@ -82,7 +82,10 @@ export default function createParser (options) {
  P(`Expected: ${JSON.stringify(e)}`, indent)
  }
 
- if (actual === expected) { // shallow test output; can't be diffed
+ if (actual === 'undefined') actual = undefined
+ if (expected === 'undefined') expected = undefined
+
+ if (actual && expected && actual === expected) { // shallow test output; can't be diffed
  P(`${_.expected('Expected')} did not match ${_.actual('actual')}.`, indent)
  P(_.dim('TAP output cannot be diffed'), indent)
  P(actual, indent)
@@ -139,15 +142,14 @@ export default function createParser (options) {
  P(`Expected "${_.actual(actual)}" to not match ${_.expected(expected)}`, indent)
  break
  case 'throws':
- // ? maybe don't handle different edges of "throws"
  if (
  actual
- && actual !== 'undefined'
+ && typeof actual !== 'undefined'
  && expected
- && expected !== 'undefined'
+ && typeof expected !== 'undefined'
  ) // this weird combination is throws with expected/assertion
  P(`Expected ${_.expected(expected)} to match "${_.actual(actual.message || actual)}"`, indent)
- else if (actual && actual !== 'undefined') // this combination is usually "doesNotThrow"
+ else if (actual && typeof actual !== 'undefined') // this combination is usually "doesNotThrow"
  P(`Expected to not throw, received "${_.actual(actual)}"`, indent)
  else
  P('Expected to throw', indent)