[website] Fix GA events going to development

[bharatkashyap]

• This is to fix Google Analytics issues going to the "development" instance of Google Analytics

See https://github.com/mui/material-ui/blob/master/docs/pages/_document.js#L34 and

• Please follow the the contributing guide on how to create great pull requests.

[render]

Your Render PR Server URL is https://toolpad-pr-899.onrender.com.

Follow its progress at https://dashboard.render.com/web/srv-ccb6q8fho1kli2o7spn0.

[bharatkashyap]

Value of

process.env.PULL_REQUEST,
  typeof process.env.PULL_REQUEST,
  JSON.stringify(process.env.PULL_REQUEST),

in the deploy preview build:

[Janpot]

Ok, I understand now. During SSR it always uses the environment variables available on the server. netlify passes PULL_REQUEST=false during production build. We are not converting process.env.PULL_REQUEST to a boolean in next.config.js (like the monorepo does). So it gets interpolated as "false", which is a truthy value, thus the Toolpad docs thinks it's always building a PR preview.

Solution, either:

• do PULL_REQUEST: process.env.PULL_REQUEST === 'true' like in the monorepo. (This is kind of brittle, it makes the value of PULL_REQUEST a string in some places, and a boolean in other. We're also relying on a variable that is defined by the CI provider)
• define process.env.GA_ID and pass the correct value in CI

[bharatkashyap]

Ok, I understand now. During SSR it always uses the environment variables available on the server. netlify passes PULL_REQUEST=false during production build. We are not converting process.env.PULL_REQUEST to a boolean in next.config.js (like the monorepo does). So it gets interpolated as "false", which is a truthy value, thus the Toolpad docs thinks it's always building a PR preview.

Solution, either:

• do PULL_REQUEST: process.env.PULL_REQUEST === 'true' like in the monorepo. (This is kind of brittle, it makes the value of PULL_REQUEST a string in some places, and a boolean in other. We're also relying on a variable that is defined by the CI provider)
• just pass process.env.GA_ID and pass the correct value in CI

Let's go ahead and take the first route for now so that we can defer to the existing way of doing things in the immediate term

[oliviertassinari]

mui/material-ui#34259 should prevent this bug from happening again, making Toolpad less coupled with the docs infra.