Support optional peer dependencies via packageJson.peerDependenciesMeta

[seanmarthur]

I am not quite sure how to properly write a test to support this use case, but this code is tested against my serverless project.

A reproduction case would be to add the knex package to a serverless project. The knex package.json looks like this:

  "peerDependencies": {
    "mssql": "^5.1.0",
    "mysql": "^2.17.1",
    "mysql2": "^1.7.0",
    "pg": "^7.12.1",
    "sqlite3": "^4.1.0"
  },
  "peerDependenciesMeta": {
    "mssql": {
      "optional": true
    },
    "mysql": {
      "optional": true
    },
    "mysql2": {
      "optional": true
    },
    "pg": {
      "optional": true
    },
    "sqlite3": {
      "optional": true
    }
  },

knex will only be used with a maximum of 1 of those peer dependencies, and they are specified as optional via the peerDependenciesMeta config. Without the code change in this PR, the build will fail, complaining about one of those dependencies being missing (Error: [serverless-plugin-include-dependencies]: Could not find mssql.)

[dougmoscrop]

cool! can you add some tests?

[dryror]

@seanmarthur I've added an example test using your code here dryror@a168712.

Would love to see this merged in, but didn't want to take over your PR. :)

@dou

[seanmarthur]

I merged the tests written by @dryror into my repo so they are now included in this PR.

Pls review/verify them - I cannot test locally at the moment.

[dryror]

@dougmoscrop any chance of getting this merged in now that there are tests? 🍻

[dougmoscrop]

Yes sorry! Today is a holiday in Canuckistan but I'll get to it tomorrow

…

On Mon., Feb. 17, 2020, 1:26 p.m. Rory Drysdale, ***@***.***> wrote: @dougmoscrop <https://github.com/dougmoscrop> any chance of getting this merged in now that there are tests? 🍻 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#44?email_source=notifications&email_token=AAEPGFERBKOLSEAUIFN7LW3RDLJGJA5CNFSM4J2FBHI2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEL7KBMQ#issuecomment-587112626>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEPGFCNS4MBZDLZFSJM62TRDLJGJANCNFSM4J2FBHIQ> .

[dryror]

Yes sorry! Today is a holiday in Canuckistan but I'll get to it tomorrow
…
On Mon., Feb. 17, 2020, 1:26 p.m. Rory Drysdale, @.***> wrote: @dougmoscrop https://github.com/dougmoscrop any chance of getting this merged in now that there are tests? 🍻 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#44?email_source=notifications&email_token=AAEPGFERBKOLSEAUIFN7LW3RDLJGJA5CNFSM4J2FBHI2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEL7KBMQ#issuecomment-587112626>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAEPGFCNS4MBZDLZFSJM62TRDLJGJANCNFSM4J2FBHIQ .

Great, thanks @dougmoscrop

[dryror]

Sorry to keep bugging you @dougmoscrop, but any chance of getting this merged in? Would love to update my knex dependency, but this is preventing me from being able to. 🍻

[dougmoscrop]

no need to apologize I appreciate the reminder*