Handle erroneous location (at) information gracefully

[aral]

Sometimes, it seems that the file location (error.at) information is not correctly populated.

e.g., I’m getting the following when tests fail because an object doesn’t exist in my current app:

{ file: '', line: undefined, character: '[as' }

Detect this and handle it gracefully.

Suggested implementation

When this is detected, look in the stack trace (if it exists) for the file:/// line and use that. e.g.,

  TypeError: utils.calculateBasePath is not a function
  at file:///var/home/aral/Projects/nodekit/tests/utils.js:120:26
  at Test.<anonymous> (/var/home/aral/Projects/nodekit/node_modules/tape-promise/index.compiled.js:86:19)
  at Test.bound [as _cb] (/var/home/aral/Projects/nodekit/node_modules/tape/lib/test.js:99:32)
  at Test.run (/var/home/aral/Projects/nodekit/node_modules/tape/lib/test.js:117:31)
  at Test.bound [as run] (/var/home/aral/Projects/nodekit/node_modules/tape/lib/test.js:99:32)
  at Immediate.next [as _onImmediate] (/var/home/aral/Projects/nodekit/node_modules/tape/lib/results.js:88:19)
  at process.processImmediate (node:internal/timers:471:21)