[Homebrew] Add homebrew downloads badge

[kdheepak]

I've added a downloads route for homebrew formulae.

I wanted to point out a few things.

As an example, the formula for cake has the following information: https://formulae.brew.sh/api/formula/cake.json

  "analytics": {
    "install": {
      "30d": {
        "cake": 93
      },
      "90d": {
        "cake": 182
      },
      "365d": {
        "cake": 922
      }
    },
    "install_on_request": {
      "30d": {
        "cake": 91
      },
      "90d": {
        "cake": 180
      },
      "365d": {
        "cake": 902
      }
    },
    "build_error": {
      "30d": {
        "cake": 0
      }
    }
  },

1. The name of the formula is in the key of the object. This is what I ended up doing:

   const schema = Joi.object({
     analytics: Joi.object({
       install: Joi.object({
         '30d': Joi.object().required(),
         '90d': Joi.object().required(),
         '365d': Joi.object().required(),
       }).required(),
     }).required(),
   }).required()

   I would have liked to do something like the following though:

   function schemaGenerator({ formula })
     return Joi.object({
       analytics: Joi.object({
         install: Joi.object({
           '30d': Joi.object({ `${formula}`: nonNegativeInteger }).required(),
           '90d': Joi.object({ `${formula}`: nonNegativeInteger }).required(),
           '365d': Joi.object({ `${formula}`: nonNegativeInteger }).required(),
         }).required(),
       }).required(),
     }).required()
   }
   
   ...
   
     async fetch({ formula }) {
       const schema = schemaGenerator({ formula }) // generate schema based on formula
       return this._requestJson({
         schema,
         url: `https://formulae.brew.sh/api/formula/${formula}.json`,
         errorMessages: { 404: 'package not found' },
       })
     }

   But I get the following error:

   [server] 0221062056 Server is starting up: http://localhost:8080/
   [server] /Users/USER/gitrepos/shields/services/homebrew/homebrew-downloads.service.js:13
   [server]        '30d': Joi.object({ `${formula}`: nonNegativeInteger }).required(),
   [server]                            ^^^
   [server]
   [server] SyntaxError: Unexpected template string
   [server]     at wrapSafe (node:internal/modules/cjs/loader:1018:16)
   [server]     at Module._compile (node:internal/modules/cjs/loader:1066:27)
   [server]     at Object.Module._extensions..js (node:internal/modules/cjs/loader:1131:10)
   [server]     at Module.load (node:internal/modules/cjs/loader:967:32)
   [server]     at Function.Module._load (node:internal/modules/cjs/loader:807:14)
   [server]     at Module.require (node:internal/modules/cjs/loader:991:19)
   [server]     at require (node:internal/modules/cjs/helpers:92:18)
   [server]     at /Users/USER/gitrepos/shields/core/base-service/loader.js:26:20
   [server]     at Array.forEach (<anonymous>)
   [server]     at loadServiceClasses (/Users/USER/gitrepos/shields/core/base-service/loader.js:25:16)
   

   As such, right now I've implemented with without validating the final depth of the data. If anyone knows how to do this let me know. I looked through the documentation for joi and javascript template strings, and I wasn't able to figure it out.

2. In the api data, there's downloads available for the last 30 days, 90 days and last 365 days. Based on other download badges for shields.io, I saw that the string /month and /year is used as part of the message. I couldn't think of a appropriate string to add for the label for 90 days, so I left it out for now. I can update the PR based on suggestions for this.

3. There's install and install_on_request fields in the data. I believe install_on_request is the download numbers when I user asks to install a package. The install download numbers include download analytics for when the package is downloaded as a dependency as well. I think install download numbers will always be greater than or equal to install_on_request download numbers. We can make it a drop down option if required.

4. I changed the version homebrew badge to have the label version instead of homebrew.

This PR will resolves #6190.

[shields-ci]

	Messages
📖	✨ Thanks for your contribution to Shields, @kdheepak!

Generated by 🚫 dangerJS against 9028a67

[lgtm-com]

This pull request introduces 1 alert when merging 38170eb into 1adfbe4 - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[chris48s]

Thanks for having a look at this. I've not read the code, but here's some answers to your questions..

1. You can use square brackets instead of a template string, which will work:

function getSchema({ formula }) {
  return Joi.object({
    analytics: Joi.object({
      install: Joi.object({
        '30d': Joi.object({ [formula]: nonNegativeInteger }).required(),
        '90d': Joi.object({ [formula]: nonNegativeInteger }).required(),
        '365d': Joi.object({ [formula]: nonNegativeInteger }).required(),
      }).required(),
    }).required(),
  }).required()
}

we normally name functions as verbNoun i.e: doThing() not thingDoer()

I couldn't think of a appropriate string to add for the label for 90 days

I'd probably call it downloads per quarter /dq.

3. Installs sounds like the metric that is most comparable with our other downloads/installs badges.

We can make it a drop down option if required.

It might be nice to at least give ourselves wiggle room in the route if we want to add it later. How about we make it homebrew/installs/:interval/:formula then if there is a clear case for adding install_on_request we can add the route in a non-confusing way.

4. Version badges should generally use the name of the package manager as the badge label:

Can you leave this as "homebrew"

[kdheepak]

I'd probably call it downloads per quarter /dq.

Homebrew doesn't seem to support having quarter in the message:

[kdheepak]

Thanks for your detailed comments! I've updated the PR based on your comments:

1. I changed the version service label back to homebrew.

2. I added a validation based on what you suggested. That worked great!

3. I changed the route to /homebrew/installs/:interval/:formula.

The only thing that I'm not able to figure out is how to get /quarter in the string of the message.

[chris48s]

No worries :) The reason the test fails with quarter is because we've not used it before so the isMetricOverTimePeriod validator doesn't know about it. You can add quarter to the regex

shields/services/test-validators.js

Lines 75 to 77 in 1adfbe4

	const isMetricOverTimePeriod = withRegex(
	/^([1-9][0-9]*[kMGTPEZY]?|[1-9]\.[1-9][kMGTPEZY])\/(year|month|four weeks|week|day)$/
	)

and I think your tests should pass

[kdheepak]

Thanks for suggestion! I made the update.

[chris48s]

Nice 👍 One final comment to address and we're good to merge.

[chris48s]

Great first contribution- thanks

[kdheepak]

Thanks for all the suggestions!

[calebcartwright]

Indeed, well done @kdheepak!

[kdheepak]

This is a very well organized piece of software and valuable resource to the community, thank you for all the time and effort you've put into it.