Reasons against enforcing Prettier globally on a code-base. Also applies to other “deterministic”/AST-based reprinting formatters such as Biome or dprint.

• The way code is formatted also conveys information and programmer’s intent. Unless a specific formatting convention breaks explicit rules, there might be multiple ways of structuring white space in code to convey different kinds of intent.

• The primary issue is printWidth enforcement (which cannot be disabled, as it is a “selling point” of the tool). When two lines are similar in function and therefore should look similar, but one sits closer to the printWidth limit, Prettier re-formats only that one, breaking the visual parallel.

  Before:

  const disable = () => updateFields({ expanded: true, active: true })
  const enable  = () => updateFields({ expanded: false, active: false })

  After Prettier:

  const disable = () => updateFields({ expanded: true, active: true })
  const enable = () =>
    updateFields({ expanded: false, active: false })

• Method chains with property extraction get exploded into multi-line blocks for no readability gain.

  Before:

  export const items = Object
    .values(lookup)
    .map(({ name, type, label, category }) => ({ name, type, label, category }))

  After Prettier:

  export const items = Object.values(lookup).map(
    ({ name, type, label, category }) => ({
      name,
      type,
      label,
      category,
    })
  );

• Intentional chain formatting in E2E tests gets collapsed. A useful convention: first line retrieves the element, subsequent lines describe actions. Prettier destroys this when short chains fit on one line but longer ones don’t.

  Before:

  cy.get('[data-testid="login-form"]')
    .find('button')
    .click()
  
  cy.get('[data-testid="settings-panel"]')
    .find('button')
    .click()
  
  cy.get('[data-testid="upload-dialog"]')
    .as('uploadDialog')
    .find('input[type="file"]')
    .as('fileInput')
    .scrollIntoView()
    .attachFile('test.csv')

  After Prettier:

  cy.get('[data-testid="login-form"]').find('button').click()
  
  cy.get('[data-testid="settings-panel"]').find('button').click()
  
  cy.get('[data-testid="upload-dialog"]')
    .as('uploadDialog')
    .find('input[type="file"]')
    .as('fileInput')
    .scrollIntoView()
    .attachFile('test.csv')

• Prefer formatters that surgically target problematic sections of code and allow space for programmer’s opinions on how to format code such as Stylistic.