fix(*): Use allOf where needed

This reverts 1957053
because the use of `allOf` is not redundant - one can note use a "bare" `$ref`.

schema/ArrayValidator.schema.yaml

@@ -9,11 +9,13 @@ properties:
   itemsValidator:
     '@id': stencila:itemsValidator
     description: Another validator node specifying the constraints on all items in the array.
-    $ref: ValidatorTypes
+    allOf:
+      - $ref: ValidatorTypes
   contains:
     '@id': stencila:contains
     description: An array node is valid if at least one of its items is valid against the `contains` schema.
-    $ref: ValidatorTypes
+    allOf:
+      - $ref: ValidatorTypes
   minItems:
     '@id': stencila:minItems
     description: An array node is valid if its size is greater than, or equal to, this value.

schema/CodeExpression.schema.yaml

@@ -9,7 +9,8 @@ properties:
   output:
     '@id': stencila:output
     description: The value of the expression when it was last evaluated.
-    $ref: Node
+    allOf:
+      - $ref: Node
   errors:
     '@id': stencila:errors
     description: Errors when compiling or executing the chunk.

schema/ConstantValidator.schema.yaml

@@ -12,4 +12,5 @@ properties:
   value:
     '@id': schema:value
     description: The value that the node must have.
-    $ref: Node
+    allOf:
+      - $ref: Node

schema/CreativeWork.schema.yaml

@@ -48,30 +48,35 @@ properties:
   dateCreated:
     '@id': schema:dateCreated
     description: Date/time of creation.
-    $ref: Date
+    allOf:
+      - $ref: Date
   dateReceived:
     '@id': schema:dateReceived
     description: Date/time that work was received.
-    $ref: Date
+    allOf:
+      - $ref: Date
   dateAccepted:
     '@id': stencila:dateAccepted
     description: Date/time of acceptance.
     $comment: |
       This is not yet a schema.org property but the term is used
       [in Dublin Core](http://purl.org/dc/terms/dateAccepted).
-    $ref: Date
+    allOf:
+      - $ref: Date
   dateModified:
     '@id': schema:dateModified
     description: Date/time of most recent modification.
-    $ref: Date
+    allOf:
+      - $ref: Date
   datePublished:
     '@id': schema:datePublished
     aliases:
       # This assumes that a user specifying `date` means the date published
       # and not the date modified or created.
       - date
     description: Date of first publication.
-    $ref: Date
+    allOf:
+      - $ref: Date
   editors:
     '@id': schema:editor
     description: People who edited the `CreativeWork`.

schema/DatatableColumn.schema.yaml

@@ -9,7 +9,8 @@ properties:
   validator:
     '@id': stencila:validator
     description: The validator to use to validate data in the column.
-    $ref: ArrayValidator
+    allOf:
+      - $ref: ArrayValidator
   values:
     '@id': stencila:values
     description: The data values of the column.

schema/Function.schema.yaml

@@ -25,4 +25,5 @@ properties:
   returns:
     '@id': stencila:returns
     description: The return type of the function.
-    $ref: ValidatorTypes
+    allOf:
+      - $ref: ValidatorTypes

schema/ImageObject.schema.yaml

@@ -13,4 +13,5 @@ properties:
   thumbnail:
     '@id': schema:thumbnail
     description: Thumbnail image of this image.
-    $ref: ImageObject
+    allOf:
+      - $ref: ImageObject

schema/ListItem.schema.yaml

@@ -22,7 +22,8 @@ properties:
     '@id': schema:item
     description: The item represented by this list item.
     $comment: Use either `item` or `content`, not both.
-    $ref: Node
+    allOf:
+      - $ref: Node
   position:
     '@id': schema:position
     description: The position of the item in a series or sequence of items.

schema/Organization.schema.yaml

@@ -72,4 +72,5 @@ properties:
     '@id': schema:parentOrganization
     description: |
       Entity that the Organization is a part of. For example, parentOrganization to a department is a university.
-    $ref: Organization
+    allOf:
+      - $ref: Organization

schema/Parameter.schema.yaml

@@ -9,7 +9,8 @@ properties:
   default:
     '@id': schema:defaultValue
     description: The default value of the parameter.
-    $ref: Node
+    allOf:
+      - $ref: Node
   isRequired:
     '@id': schema:valueRequired
     description: Is this parameter required, if not it should have a default or default is assumed to be null.

schema/PropertyValue.schema.yaml

@@ -23,6 +23,7 @@ properties:
   value:
     '@id': schema:value
     description: The value of the property.
-    $ref: Node
+    allOf:
+      - $ref: Node
 required:
   - value

schema/SoftwareSession.schema.yaml

@@ -14,15 +14,18 @@ properties:
   environment:
     '@id': stencila:environment
     description: The software environment to execute this session in.
-    $ref: SoftwareEnvironment
+    allOf:
+      - $ref: SoftwareEnvironment
   dateStart:
     '@id': schema:startDate
     description: The date-time that the session began.
-    $ref: Date
+    allOf:
+      - $ref: Date
   dateEnd:
     '@id': schema:endDate
     description: The date-time that the session ended.
-    $ref: Date
+    allOf:
+      - $ref: Date
   status:
     '@id': stencila:sessionStatus
     description: The status of the session (starting, stopped, etc).

schema/Variable.schema.yaml

@@ -25,10 +25,12 @@ properties:
   validator:
     '@id': stencila:validator
     description: The validator that the value is validated against.
-    $ref: ValidatorTypes
+    allOf:
+      - $ref: ValidatorTypes
   value:
     '@id': schema:value
     description: The value of the variable.
-    $ref: Node
+    allOf:
+      - $ref: Node
 required:
   - name

schema/VideoObject.schema.yaml

@@ -13,7 +13,8 @@ properties:
   thumbnail:
     '@id': schema:thumbnail
     description: Thumbnail image of this video recording.
-    $ref: ImageObject
+    allOf:
+      - $ref: ImageObject
   transcript:
     '@id': schema:transcript
     description: The transcript of this video recording.

ts/schema.ts

@@ -136,7 +136,6 @@ export const readSchema = async (type: string): Promise<JsonSchema> => {
  * - each `@id` is associated with only one property name or type `title`
  * - no duplicate `stencila:` `@ids` (case insensitive)
  * - that other schemas that are referred to in `extends` or `$ref` exist
- * - that `anyOf` and `allOf` for properties have at least two items
  * - that no ordering is required for `array` properties
  *
  * @param schemas A map of all the schemas
@@ -222,21 +221,9 @@ const checkSchema = (
       else if (property.description.length > maxDescriptionLength)
         error(`${title}.${name}.description is too long`)
 
-      if (property.anyOf && property.anyOf.length < 2) {
-        error(
-          `${title}.${name}.anyOf has less than two items, is it necessary?`
-        )
-      }
-
-      if (property.allOf && property.allOf.length < 2) {
-        error(
-          `${title}.${name}.allOf has less than two items, is it necessary?`
-        )
-      }
-
       if (property.type === 'array' && Array.isArray(property.items)) {
         error(
-          `${title}.${name}.items is using ordered validation, use plain 'ref' or 'anyOf' instead?`
+          `${title}.${name}.items is using ordered validation, use plain '$ref' or 'anyOf' instead?`
         )
       }
     }