Make start required arguments more explicit

[camerondurham]

Problem Description

One small papercut while starting to use this tools was what arguments were really required to "start" a new task.

The current help for bartib start does not show any required arguments or flags:

bartib start -h
bartib-start
starts a new activity

USAGE:
    bartib start [OPTIONS]

FLAGS:
    -h, --help    Prints help information

OPTIONS:
    -d, --description <DESCRIPTION>    the description of the new activity
    -p, --project <PROJECT>            the project to which the new activity belongs
    -t, --time <TIME>                  the time for changing the activity status (HH:MM)

However, when I attempt to use as is, it of course needs some data to actually start an activity:

bartib start -d "test descr"
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', ...
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Possible Solutions

Of course, there are multiple ways to help with this. Here are a few I thought of:

1. make description and project flags explicit through clap args
2. do input validation in the controller, likely around here: https://github.com/nikolassv/bartib/blob/master/src/controller/manipulation.rs#L29-L33
3. do input validation in Activity::start https://github.com/nikolassv/bartib/blob/master/src/data/activity.rs#L26
4. make only project arg required, default description to empty string (or other design related change)

I'm sure there are other ways but (1) seemed like the easiest so I sent a quick PR.

Testing

Validating new args have expected help after cargo build --release

start command help makes required args more explicit

./target/release/bartib start -h
bartib-start
starts a new activity

USAGE:
    bartib start [OPTIONS] --description <DESCRIPTION> --project <PROJECT>

FLAGS:
    -h, --help    Prints help information

OPTIONS:
    -d, --description <DESCRIPTION>    the description of the new activity
    -p, --project <PROJECT>            the project to which the new activity belongs
    -t, --time <TIME>                  the time for changing the activity status (HH:MM)

continue command args are unchanged

./target/release/bartib continue -h
bartib-continue
continues a previous activity

USAGE:
    bartib continue [OPTIONS] [NUMBER]

FLAGS:
    -h, --help    Prints help information

OPTIONS:
    -d, --description <DESCRIPTION>    the description of the new activity
    -p, --project <PROJECT>            the project to which the new activity belongs
    -t, --time <TIME>                  the time for changing the activity status (HH:MM)

ARGS:
    <NUMBER>    the number of the activity to continue (see subcommand `last`) [default: 0]

Validating required flag shows more helpful error message:

Error 1: no project provided

./target/release/bartib start -d "test"
error: The following required arguments were not provided:
    --project <PROJECT>

USAGE:
    bartib start [OPTIONS] --description <DESCRIPTION> --project <PROJECT>

For more information try --help

Error 2: no description provided

./target/release/bartib start -p "test"
error: The following required arguments were not provided:
    --description <DESCRIPTION>

USAGE:
    bartib start [OPTIONS] --description <DESCRIPTION> --project <PROJECT>

For more information try --help

Happy case: all args provided

./target/release/bartib start -p "test project" -d "test description"
Stopped activity: "write general SOP for all application levers" (availability lever SOP) started at 2021-11-16 18:17 (05m)
Started activity: "test description" (test project) at 2021-11-16 18:22

[nikolassv]

Thank you! This is a real improvement. And I agree with you: Making both arguments required via clap is the best solution.