Print error message when no matches are found by --filter or --regex flag

[ericstoekl]

Print error message when no matches are found by --filter or --regex flag

Signed-off-by: Eric Stoekl ems5311@gmail.com

Description

This change is to return an error message when all functions are filtered out by the --filter or --regex option. The current error message is "No functions found in YAML, check --filter/--regex".

Motivation and Context

• I have raised an issue to propose this change (required)
  Issue Print error message when --filter or --regex returns no matches #124

This will help users figure out what is wrong with their command if they expect functions to be deployed, and nothing happens.

How Has This Been Tested?

Tests were upgraded to accommodate this change and check for this error to be properly thrown when --filter and --regex remove all functions.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[open-derek]

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That's something we need before your Pull Request can be merged. Please see our contributing guide.

[ericstoekl]

Just added some extra test functionality, to test that when we expect an error message was returned, to verify that it is the correct error message.

[alexellis]

This message was deleted?

[ericstoekl]

There is already an error thrown by the regex parser when the regex is invalid, which gets printed out by each command which calls ParseYAMLFile() by its following error checking block:

if err != nil {
    log.Fataln(err.Error())
    return
}

The line that log.Fataln(err) prints is error parsing regexp: if it's a regex error, so I figured this printf is redundant. Also, for testing, I wanted to confirm the error message, and only have one line print out makes that easier.

[alexellis]

As long as you bubble up the error.

[alexellis]

Very good improvement to the UX here @ericstoekl

[alexellis]

Can you include the expected messages for given error scenarios below?

[ericstoekl]

Expected errors so far:

1. No matches found for --filter or --regex parameter: No functions matching --filter/--regex were found in the YAML file
2. Invalid regex used: error parsing regexp: <details about how to fix regex>

For example, if I use the command faas-cli build -f samples.yml --regex [, I get the message:

error parsing regexp: missing closing ]: `[`

These are the only two errors I've encountered so far related to --filter and --regex.

[alexellis]

Great. Can you now squash your commits or at least sign all of them?

git reset HEAD~2
git add .
git commit -s -m "COMMIT MESSAGE"
git push .... --force

[johnmccabe]

Could get rid of the expectedErrorMsg and change expectError to a string, use len(test.expectError) > 0 for the conditional - avoids having the redundant variable since you're always checking for the message.

[ericstoekl]

Thanks John, will update this evening.

[johnmccabe]

See earlier comment if len(test.expectError) > 0 {

[ericstoekl]

Addressed the suggestions from @johnmccabe , and squashed the commits

[alexellis]

LGTM