adding verbose output for statement execution

[vperiyasamy]

Adding a verbose command line flag to allow users to print the result of each statement execution. Should not disrupt the existing flow for users as it's completely optional. Summary of changes:

• new verbose flag
• new field for db to print result of migrations
• new interface methods for drivers to pass verbose flag
• capture and print of result for every exec based on verbose flag across db and drivers

[vperiyasamy]

changed name from --verbose because urfave cli was panicking at redefining the flag v. new flag is now called print-result

[vperiyasamy]

@amacneil - not sure how to assign reviewers

[amacneil]

Hey, sorry for the delay on this, it has been a busy few days.

Some quick thoughts/feedback:

• I think it would make more sense for the flag to exist on the command, rather than globally (it's a urfave/cli thing). So this would make the argument dbmate up --verbose rather than dbmate --verbose up. I assume that might also fix your problem with overloading the -v shorthand.
• Any thoughts on how to test this?
• What does the output look like? Is it worth formatting that result struct to make it prettier?

Otherwise looks good, thanks for the contribution!

[vperiyasamy]

thanks for the comments, no worries. I think I've addressed these concerns with the new commit:

• moved flag to subcommands for up, migrate, and rollback - you were right, I am able to use verbose now
• I added a test in db_test.go which captures the stdout and makes sure it reports the Rows affected value
• output is a formatted string I've created, you can see it in utils.go
• originally in this PR I had added verbose statements to all of the driver execution results, but after testing I found out that these have no effect because there is no InsertId or RowsAffected for those commands, so have removed those 👍

[vperiyasamy]

@amacneil bump

[vperiyasamy]

@amacneil sorry for the pestering, but any chance you would be able to look at this soon? we feel that without this logging we are missing a crucial sanity check when running our db migrations at scale

[amacneil]

Cool, this looks good. Sorry I have been busy lately and not much time for OSS. I added you as a contributor, so if you're happy with it and it's passing CI feel free to merge!

[vperiyasamy]

@amacneil thank you! no worries, I appreciate it.