## Changes
We had a number of copies of test helpers for `io/fs` in the repository.
This change consolidates all of them to use the `libs/fakefs` package.
## Tests
Unit tests pass.
## Changes
If we're using a `vfs.Path` backed by a workspace filesystem filer, we
have access to the `workspace.ObjectInfo` value for every file. By
providing access to this value we can use it directly and avoid reading
the first line of the underlying file.
A follow-up change will implement the interface defined in this change
for the workspace filesystem filer.
## Tests
Unit tests.
## Changes
From the [documentation](https://pkg.go.dev/os#IsNotExist) on the
functions in the `os` package:
> This function predates errors.Is. It only supports errors returned by
the os package.
> New code should use errors.Is(err, fs.ErrNotExist).
This issue surfaced while working on using a different `vfs.Path`
implementation that uses errors from the `fs` package. Calls to
`os.IsNotExist` didn't return true for errors that wrap
`fs.ErrNotExist`.
## Tests
n/a
Adds check for whether file exists locally
case 1: local (relative) file does not exist
```
foo:
name: "[job-output] test-job by shreyas"
tasks:
- task_key: my_notebook_task
existing_cluster_id: ***
notebook_task:
notebook_path: "./doesnotexist"
```
output:
```
shreyas.goenka@THW32HFW6T job-output % bricks bundle deploy
Error: notebook ./doesnotexist not found. Error: open /Users/shreyas.goenka/projects/job-output/doesnotexist: no such file or directory
```
case 2: remote (absolute) file does not exist
```
foo:
name: "[job-output] test-job by shreyas"
tasks:
- task_key: my_notebook_task
existing_cluster_id: ***
notebook_task:
notebook_path: "/Users/shreyas.goenka@databricks.com/doesnotexist"
```
output:
```
shreyas.goenka@THW32HFW6T job-output % bricks bundle deploy
shreyas.goenka@THW32HFW6T job-output % bricks bundle run foo
Error: failed to reach TERMINATED or SKIPPED, got INTERNAL_ERROR: Task my_notebook_task failed with message: Notebook not found: /Users/shreyas.goenka@databricks.com/doesnotexist. This caused all downstream tasks to get skipped.
```
case 3: remote exists
Successful deploy and run
Files with extension `.ipynb` are imported are Jupyter notebooks.
This code detects 1) if the file is a valid Jupyter notebook and 2) the
Databricks specific language it contains.