docs(gatsby-source-wordpress): Remove lodash + bluebird + fix Promise hell

[DylanTackoor]

Description

This commit:

• Removes lodash in favor of Array.forEach
• Bluebird in favor of the native Promise object
• Avoids nested thenables by using Promise.all()

I've been using this code in my builds and it's been working fine for whatever that worth :)

[DylanTackoor]

Looks like the Azure Pipeline task has a bug pulling something with Yarn, but the code works otherwise 😱

2019-02-13T15:46:04.3801464Z ##[section]Starting: CmdLine
2019-02-13T15:46:04.3911190Z ==============================================================================
2019-02-13T15:46:04.3911250Z Task         : Command Line
2019-02-13T15:46:04.3911288Z Description  : Run a command line script using cmd.exe on Windows and bash on macOS and Linux.
2019-02-13T15:46:04.3911345Z Version      : 2.146.1
2019-02-13T15:46:04.3911378Z Author       : Microsoft Corporation
2019-02-13T15:46:04.3911415Z Help         : [More Information](https://go.microsoft.com/fwlink/?LinkID=613735)
2019-02-13T15:46:04.3911468Z ==============================================================================
2019-02-13T15:46:05.7867622Z Generating script.
2019-02-13T15:46:05.7991716Z Script contents:
2019-02-13T15:46:05.7998822Z yarn bootstrap
2019-02-13T15:46:05.8597677Z ##[command]"C:\windows\system32\cmd.exe" /D /E:ON /V:OFF /S /C "CALL "D:\a\_temp\bd085075-59cf-4de0-85c0-3b4f065420e8.cmd""
2019-02-13T15:46:15.0653626Z yarn run v1.13.0
2019-02-13T15:46:15.1773258Z $ yarn
2019-02-13T15:46:16.5975153Z [1/4] Resolving packages...
2019-02-13T15:46:18.2236144Z [2/4] Fetching packages...
2019-02-13T15:47:28.6084712Z error An unexpected error occurred: "https://registry.yarnpkg.com/@xtuc/long/-/long-4.2.1.tgz: Request failed \"502 Bad Gateway\"".
2019-02-13T15:47:28.6085038Z info If you think this is a bug, please open a bug report with the information provided in "D:\\a\\1\\s\\yarn-error.log".
2019-02-13T15:47:28.6085885Z info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
2019-02-13T15:47:38.7696222Z error Command failed with exit code 1.
2019-02-13T15:47:38.7697806Z info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
2019-02-13T15:47:39.0497956Z ##[error]Cmd.exe exited with code '1'.
2019-02-13T15:47:39.0894802Z ##[section]Finishing: CmdLine

[DSchau]

Yeah - this is generally cleaner.

Would you be interested in refactoring with async/await? (see #11548 for more info on that!)

[DylanTackoor]

Would you be interested in refactoring with async/await? (see #11548 for more info on that!)

I initially had an async/await version but decided on this approach as Promise.all() should be faster as both Promises execute in parallel this way :D

[DSchau]

@DylanTackoor you can (and should!) use Promise.all with async/await ;)

Using one does not preclude the other.

[DylanTackoor]

Sweet, thanks for the tip! I'll update the PR later today when I have a chance 😊

[DylanTackoor]

@DSchau I ended up avoiding using Promise.all() in favor of a single async GraphQL query. Thoughts?

[DSchau]

Looking better!

Unfortunately, we don't throw errors if a GraphQL query has errors (so you can still use the GraphiQL editor to try and debug queries), we use an errors property on the returned object from the graphql call.

So you'll want to remove the try/catch, and rather do something like

const result = await graphql(``)

if (result.errors) {
  throw new Error(result.errors)
}

if you want to stop execution and alert of errors.

[DylanTackoor]

Fixed it! Also took the chance to destructure the data property.

[wardpeet]

Merged master and ran prettier

@DSchau mind taking another look?

[DSchau]

Let's do it; thanks for this, think it's a big improvement! Also co-locating the queries instead of a Promise.all was a nice tweak!

[gatsbot]

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