withamp-to-config.ts

// One-time usage file. You can delete me after running the codemod!

function injectAmp(j, o, desiredAmpValue) {
  const init = o.node.init

  switch (init.type) {
    case 'ObjectExpression': {
      const overwroteAmpKey = init.properties.some((prop) => {
        switch (prop.type) {
          case 'Property':
          case 'ObjectProperty':
            if (!(prop.key.type === 'Identifier' && prop.key.name === 'amp')) {
              return false
            }

            prop.value = desiredAmpValue
            return true
          default:
            return false
        }
      })

      if (!overwroteAmpKey) {
        init.properties.push(
          j.objectProperty(j.identifier('amp'), desiredAmpValue)
        )
      }

      return true
    }
    default: {
      return false
    }
  }
}

export default function transformer(file, api) {
  const j = api.jscodeshift.withParser('tsx')
  const root = j(file.source)
  const done = () => root.toSource()

  const imports = root.find(j.ImportDeclaration, {
    source: { value: 'next/amp' },
  })

  if (imports.length < 1) {
    return
  }

  let hadWithAmp = false
  const ampImportNames = []

  imports.forEach((ampImport) => {
    const ampImportShift = j(ampImport)

    const withAmpImport = ampImportShift.find(j.ImportSpecifier, {
      imported: { name: 'withAmp' },
    })

    if (withAmpImport.length < 1) {
      return
    }

    hadWithAmp = true
    withAmpImport.forEach((element) => {
      ampImportNames.push(element.value.local.name)
      j(element).remove()
    })

    if (ampImport.value.specifiers.length === 0) {
      ampImportShift.remove()
    }
  })

  if (!hadWithAmp) {
    return done()
  }

  const defaultExportsShift = root.find(j.ExportDefaultDeclaration)
  if (defaultExportsShift.length < 1) {
    return done()
  }

  let desiredAmpValue = j.booleanLiteral(true)

  const defaultExport = defaultExportsShift.nodes()[0]
  const removedWrapper = ampImportNames.some((ampImportName) => {
    const ampWrapping = j(defaultExport).find(j.CallExpression, {
      callee: { name: ampImportName },
    })

    if (ampWrapping.length < 1) {
      return false
    }

    ampWrapping.forEach((e) => {
      if (e.value.arguments.length < 1) {
        j(e).remove()
      } else {
        const withAmpOptions = e.value.arguments[1]
        if (withAmpOptions && withAmpOptions.type === 'ObjectExpression') {
          const isHybrid = withAmpOptions.properties.some((prop) => {
            if (!(prop.type === 'Property' || prop.type === 'ObjectProperty')) {
              return false
            }

            if (!(prop.key && prop.key.name === 'hybrid')) {
              return false
            }

            return (
              (prop.value.type === 'Literal' ||
                prop.value.type === 'BooleanLiteral') &&
              prop.value.value === true
            )
          })

          if (isHybrid) {
            desiredAmpValue = j.stringLiteral('hybrid')
          }
        }

        j(e).replaceWith(e.value.arguments[0])
      }
    })
    return true
  })

  if (!removedWrapper) {
    return done()
  }

  const namedExportsShift = root.find(j.ExportNamedDeclaration)
  const hadExistingConfig = namedExportsShift.some((namedExport) => {
    const configExportedObject = j(namedExport).find(j.VariableDeclarator, {
      id: { name: 'config' },
    })
    if (configExportedObject.length > 0) {
      return configExportedObject.some((exportedObject) =>
        injectAmp(j, exportedObject, desiredAmpValue)
      )
    }

    const configReexported = j(namedExport).find(j.ExportSpecifier, {
      local: { name: 'config' },
    })
    if (configReexported.length > 0) {
      const configObjects = root
        .findVariableDeclarators('config')
        .filter((el) => el.scope.isGlobal)
      return configObjects.some((configObject) =>
        injectAmp(j, configObject, desiredAmpValue)
      )
    }

    return false
  })

  if (!hadExistingConfig) {
    defaultExportsShift.insertAfter(
      j.exportNamedDeclaration(
        j.variableDeclaration('const', [
          j.variableDeclarator(
            j.identifier('config'),
            j.objectExpression([
              j.objectProperty(j.identifier('amp'), desiredAmpValue),
            ])
          ),
        ])
      )
    )
  }

  return done()
}