Schema Intersection

I try to create the following model:

type Asset = {
  status: 'created' | 'removed'
} & (
  | {
      type: 'image'
      src: string
    }
  | {
      type: 'text'
      value: string
    }
)

type Asset = {
  status: 'created' | 'removed'
} & (
  | {
      type: 'image'
      src: string
    }
  | {
      type: 'text'
      value: string
    }
)

I've read about unions at the top level here: https://docs.convex.dev/database/schemas#unions However, as you can see, I need the status field that is true for all asset types. I tried to do this:

defineSchema({
  assets: defineTable({
    status: v.string(), // union of literals
    ...v.union( // Argument of type is not assignable to parameter of type Record<string, GenericValidator>
      v.object({type: v.literal('image'), src: v.string()}),
      v.object({type: v.literal('text'), value: v.string()})
    )
  })
})

defineSchema({
  assets: defineTable({
    status: v.string(), // union of literals
    ...v.union( // Argument of type is not assignable to parameter of type Record<string, GenericValidator>
      v.object({type: v.literal('image'), src: v.string()}),
      v.object({type: v.literal('text'), value: v.string()})
    )
  })
})

For now, I can't understand how to implement the aforementioned type. Seems like it lacks v.intersection() API.

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5 Replies

DelveroffOP•5mo ago

Also, I wouldn't like to create a nested object since I have to index by type

Michal Srb•5mo ago

Simple:

assets: defineTable(
    v.union(
      v.object({
        status: v.string(),
        type: v.literal("image"),
        src: v.string(),
      }),
      v.object({
        status: v.string(),
        type: v.literal("text"),
        value: v.string(),
      }),
    ),
  ),

assets: defineTable(
    v.union(
      v.object({
        status: v.string(),
        type: v.literal("image"),
        src: v.string(),
      }),
      v.object({
        status: v.string(),
        type: v.literal("text"),
        value: v.string(),
      }),
    ),
  ),

Fancy:

const shared = {
  status: v.string(),
};

export default defineSchema({
  assets: defineTable(
    v.union(
      v.object({
        ...shared,
        type: v.literal("image"),
        src: v.string(),
      }),
      v.object({
        ...shared,
        type: v.literal("text"),
        value: v.string(),
      }),
    ),
  ),
});

const shared = {
  status: v.string(),
};

export default defineSchema({
  assets: defineTable(
    v.union(
      v.object({
        ...shared,
        type: v.literal("image"),
        src: v.string(),
      }),
      v.object({
        ...shared,
        type: v.literal("text"),
        value: v.string(),
      }),
    ),
  ),
});

Fanciest:

const shared = v.object({
  status: v.string(),
});

export default defineSchema({
  assets: defineTable(
    v.union(
      v.object({
        ...shared.fields,
        type: v.literal("image"),
        src: v.string(),
      }),
      v.object({
        ...shared.fields,
        type: v.literal("text"),
        value: v.string(),
      }),
    ),
  ),
});

const shared = v.object({
  status: v.string(),
});

export default defineSchema({
  assets: defineTable(
    v.union(
      v.object({
        ...shared.fields,
        type: v.literal("image"),
        src: v.string(),
      }),
      v.object({
        ...shared.fields,
        type: v.literal("text"),
        value: v.string(),
      }),
    ),
  ),
});

DelveroffOP•5mo ago

Thought exactly the same thing. Thanks! Also thought about the following:

export const assetObject(defs: any) => v.object({ // still figure out typings
  status: v.string(),
  ...defs
})

export default defineSchema({
  assets: defineTable(
    v.union(
      assetObject({
        type: v.literal('video')
      })
    )
  )
})

export const assetObject(defs: any) => v.object({ // still figure out typings
  status: v.string(),
  ...defs
})

export default defineSchema({
  assets: defineTable(
    v.union(
      assetObject({
        type: v.literal('video')
      })
    )
  )
})

Michal Srb•5mo ago

Doable but harder to type annotate Maybe @ian could build this into convex-helpers, I can see this being a fairly general pattern.

sshader•5mo ago

Also, I wouldn't like to create a nested object since I have to index by type

If you're talking about Convex indexes, you can define indexes on nested properties!

Schema Intersection

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