GROQ Syntax Error: Conditional Field Selection for Multiple Document Types

Not silly at all! This is a common syntax issue with conditional projections in GROQ. The problem is that you're trying to use a conditional projection syntax that doesn't exist in GROQ.

The syntax { _type == "footer" => { ... } } isn't valid GROQ. What you're looking for is to use conditional projections inside the main projection object, not nested in another set of curly braces.

Here's the correct approach:

*[_type in ["banner", "footer"]] {
  _type,
  _type == "footer" => {
    footerField1,
    footerField2
  },
  _type == "banner" => {
    bannerField1,
    bannerField2
  }
}

The key difference from your original query is that the conditional (_type == "footer" =>) should be inside the main projection object as a direct property, not wrapped in extra curly braces.

According to the GROQ pipeline components documentation, the conditional projection syntax condition => {} expands the object on the right-hand side into the projection when the condition evaluates to true. This syntax is exactly equivalent to ...select(condition => {}).

So when you write:

{
  _type == "footer" => {
    footerField1,
    footerField2
  }
}

GROQ evaluates the condition and if it's true, it expands those fields into the main projection object.

The error "expected '}' following object body" happened because GROQ saw your nested { ... } structure and got confused about where the projection object ended. The conditional operator => creates a conditional field directly, without needing the extra wrapper braces you had.