update CollectFields algorithm

yaacovCR · yaacovCR · commit af7705374815 · 2023-03-27T06:30:44.000+03:00
diff --git a/spec/Section 6 -- Execution.md b/spec/Section 6 -- Execution.md
@@ -739,10 +739,10 @@ Information about all fields sharing a response key are stored within Field
 Group records, structures containing:
 
 - {parentType}: the type of the parent object for this field.
+- {fieldName}: the name of this field.
 - {fields}: a map of lists of collected field nodes, indexed by the Defer
   Details record corresponding to the originating enclosing deferred fragment,
-  or {undefined} if the field is not contained by a deferred fragment.
-- {fieldDef}: the field definition for this field.
+  or by {undefined} if the field is not contained by a deferred fragment.
 - {streamDetails}: information derived from any `@stream` directive on this
   field.
 - {priority}: the overall priority for this field group, equivalent to the
@@ -767,20 +767,18 @@ fragment ExampleFragment on Query {
     subfield2
   }
   b
-}
+}run
 ```
 
 The depth-first-search order of the field groups produced by {CollectFields()}
 is maintained through execution, ensuring that fields appear in the executed
 response in a stable and predictable order.
 
 CollectFields(objectType, selectionSet, variableValues, visitedFragments,
-deferredGroupedFieldsList):
+priority, parentFieldGroup, deferredFragment):
 
-- If {visitedFragments} is not provided, initialize it to the empty set.
-- Initialize {groupedFields} to an empty ordered map of lists.
-- If {deferredGroupedFieldsList} is not provided, initialize it to an empty
-  list.
+- Initialize {groupedFieldSet} to an empty ordered map of Field Group records.
+- Initialize {deferredFragments} to an empty map of Defer Details records.
 - For each {selection} in {selectionSet}:
   - If {selection} provides the directive `@skip`, let {skipDirective} be that
     directive.
@@ -795,9 +793,30 @@ deferredGroupedFieldsList):
   - If {selection} is a {Field}:
     - Let {responseKey} be the response key of {selection} (the alias if
       defined, otherwise the field name).
-    - Let {groupForResponseKey} be the list in {groupedFields} for
-      {responseKey}; if no such list exists, create it as an empty list.
-    - Append {selection} to the {groupForResponseKey}.
+    - Let {groupForResponseKey} be the entry in in {groupedFieldSet} for
+      {responseKey}.
+    - If {groupForResponseKey} is {undefined}:
+      - Let {fieldName} be the name of {selection}.
+      - Initialize {fields} to an empty map of lists of collected field nodes,
+        indexed by originating Defer Details record, or by {undefined}.
+      - Let {listForDeferredFragment} be a list containing {selection}.
+      - Set the entry for {deferredFragment} in {fields} to
+        {listForDeferredFragment}.
+      - If {selection} provides the directive `@stream` and its {if} argument is
+        not {false} and is not a variable in {variableValues} with the value
+        {false}, let {streamDirective} be that directive.
+      - Let {groupForResponseKey} be a new Field Group record created from
+        {runtimeType}, {fieldName}, {fields}, {streamDetails}, {priority}, and
+        {parentFieldGroup}.
+    - Otherwise:
+      - Let {fields} be the corresponding entry on {groupForResponseKey}.
+      - Let {listForDeferredFragment} be the list in {fields} for
+        {deferredFragment}; if no such list exists, create it as an empty list.
+      - Append {selection} to {listForDeferredFragment}.
+      - Let {fieldGroupPriority} be the value of the {priority} entry on
+        {fieldGroup}.
+      - If {priority} is less than {fieldGroupPriority}, update the {priority}
+        entry on {fieldGroup} to {priority}.
   - If {selection} is a {FragmentSpread}:
     - Let {fragmentSpreadName} be the name of {selection}.
     - If {fragmentSpreadName} provides the directive `@defer` and its {if}
@@ -818,24 +837,61 @@ deferredGroupedFieldsList):
     - If {DoesFragmentTypeApply(objectType, fragmentType)} is false, continue
       with the next {selection} in {selectionSet}.
     - Let {fragmentSelectionSet} be the top-level selection set of {fragment}.
+    - Let {maybeNewDefer} be equal to {deferDirective}.
+    - Let {maybeIncreasedPriority} be equal to {priority}.
     - If {deferDirective} is defined:
+      - If {parentFieldGroup} is {undefined}, set {maybeIncreasedPriority} to 1.
+      - Otherwise:
+        - Let {parentFieldGroupPriority} be the value of the {priority} entry on
+          {parentFieldGroup}.
+        - If {maybeIncreasedPriority} is equal to {parentFieldGroupPriority},
+          set {maybeIncreasedPriority} to {maybeIncreasedPriority} + 1.
       - Let {label} be the value or the variable to {deferDirective}'s {label}
         argument.
-      - Let {deferredGroupedFields} be the result of calling
-        {CollectFields(objectType, fragmentSelectionSet, variableValues,
-        visitedFragments, deferredGroupedFieldsList)}.
-      - Append a record containing {label} and {deferredGroupedFields} to
-        {deferredGroupedFieldsList}.
-      - Continue with the next {selection} in {selectionSet}.
-    - Let {fragmentGroupedFieldSet} be the result of calling
-      {CollectFields(objectType, fragmentSelectionSet, variableValues,
-      visitedFragments, deferredGroupedFieldsList)}.
-    - For each {fragmentGroup} in {fragmentGroupedFieldSet}:
-      - Let {responseKey} be the response key shared by all fields in
-        {fragmentGroup}.
-      - Let {groupForResponseKey} be the list in {groupedFields} for
-        {responseKey}; if no such list exists, create it as an empty list.
-      - Append all items in {fragmentGroup} to {groupForResponseKey}.
+      - Let {existingDefer} be the record in {deferredFragments} for {label}.
+      - If {existingDefer} is undefined:
+        - Set {maybeNewDefer} equal to a new Deferred Details record created
+          from {label} and {maybeIncreasedPriority}.
+        - Set the record in {deferredFragments} for {label} to {maybeNewDefer}.
+      - Otherwise, set {maybeNewDefer} to {existingDefer}.
+    - Let {fragmentGroupedFieldSet} and {fragmentDeferredFragments} be the
+      result of calling {CollectFields(objectType, fragmentSelectionSet,
+      variableValues, visitedFragments, maybeIncreasedPriority,
+      parentFieldGroup, maybeNewDefer)}.
+    - For each {label} and {fragmentDeferredFragment} in
+      {fragmentDeferredFragments}:
+      - Let {deferredFragment} be the record in {deferredFragments} for {label}.
+      - If {deferredFragment} is {undefined}:
+        - Set the record in {deferredFragments} for {label} to
+          {fragmentDeferredFragment}.
+    - For each {responseKey} and {fragmentGroup} in {fragmentGroupedFieldSet}:
+      - Let {groupForResponseKey} be the record in {groupedFieldSet} for
+        {responseKey}.
+      - If {groupForResponseKey} is {undefined}, set the record in
+        {groupedFieldSet} for {responseKey} to {fragmentGroup}.
+      - Otherwise:
+        - Let {fieldGroupPriority} be equal to the {priority} entry on
+          {fragmentGroup}.
+        - Let {fragmentGroupPriority} be equal to the {priority} entry on
+          {fragmentGroup}.
+        - If {fragmentGroupPriority} is less than {fieldGroupPriority}, update
+          the {priority} entry on {fieldGroup} to {fragmentGroupPriority}.
+        - Let {fields} be the corresponding entry on {groupForResponseKey}.
+        - Let {fragmentFields} be equal to the {fields} entry on
+          {fragmentGroup}.
+        - For each {fragmentDeferredFragment} and
+          {fragmentListForDeferredFragment} in {fragmentFields}:
+          - Let {label} be the corresponding entry in
+            {fragmentDeferredFragment}.
+          - Let {deferredFragment} be the record in {deferredFragments} for
+            {label}.
+          - Let {listForDeferredFragment} be the record in {fields} for
+            {deferredFragment}.
+          - If {listForDeferredFragment} is {undefined}, set the record in
+            {fields} for {deferredFragment} to
+            {fragmentListForDeferredFragment}.
+          - Otherwise, append all items in {fragmentListForDeferredFragment} to
+            {listForDeferredFragment}.
   - If {selection} is an {InlineFragment}:
     - Let {fragmentType} be the type condition on {selection}.
     - If {fragmentType} is not {null} and {DoesFragmentTypeApply(objectType,
@@ -848,24 +904,62 @@ deferredGroupedFieldsList):
       - Let {deferDirective} be that directive.
       - If this execution is for a subscription operation, raise a _field
         error_.
+    - Let {fragmentSelectionSet} be the top-level selection set of {fragment}.
+    - Let {maybeNewDefer} be equal to {deferDirective}.
+    - Let {maybeIncreasedPriority} be equal to {priority}.
     - If {deferDirective} is defined:
+      - If {parentFieldGroup} is {undefined}, set {maybeIncreasedPriority} to 1.
+      - Otherwise:
+        - Let {parentFieldGroupPriority} be the value of the {priority} entry on
+          {parentFieldGroup}.
+        - If {maybeIncreasedPriority} is equal to {parentFieldGroupPriority},
+          set {maybeIncreasedPriority} to {maybeIncreasedPriority} + 1.
       - Let {label} be the value or the variable to {deferDirective}'s {label}
         argument.
-      - Let {deferredGroupedFields} be the result of calling
-        {CollectFields(objectType, fragmentSelectionSet, variableValues,
-        visitedFragments, deferredGroupedFieldsList)}.
-      - Append a record containing {label} and {deferredGroupedFields} to
-        {deferredGroupedFieldsList}.
-      - Continue with the next {selection} in {selectionSet}.
-    - Let {fragmentGroupedFieldSet} be the result of calling
-      {CollectFields(objectType, fragmentSelectionSet, variableValues,
-      visitedFragments, deferredGroupedFieldsList)}.
-    - For each {fragmentGroup} in {fragmentGroupedFieldSet}:
-      - Let {responseKey} be the response key shared by all fields in
-        {fragmentGroup}.
-      - Let {groupForResponseKey} be the list in {groupedFields} for
-        {responseKey}; if no such list exists, create it as an empty list.
-      - Append all items in {fragmentGroup} to {groupForResponseKey}.
+      - Let {existingDefer} be the record in {deferredFragments} for {label}.
+      - If {existingDefer} is undefined:
+        - Set {maybeNewDefer} equal to a new Deferred Details record created
+          from {label} and {maybeIncreasedPriority}.
+        - Set the record in {deferredFragments} for {label} to {maybeNewDefer}.
+      - Otherwise, set {maybeNewDefer} to {existingDefer}.
+    - Let {fragmentGroupedFieldSet} and {fragmentDeferredFragments} be the
+      result of calling {CollectFields(objectType, fragmentSelectionSet,
+      variableValues, visitedFragments, maybeIncreasedPriority,
+      parentFieldGroup, maybeNewDefer)}.
+    - For each {label} and {fragmentDeferredFragment} in
+      {fragmentDeferredFragments}:
+      - Let {deferredFragment} be the record in {deferredFragments} for {label}.
+      - If {deferredFragment} is {undefined}:
+        - Set the record in {deferredFragments} for {label} to
+          {fragmentDeferredFragment}.
+    - For each {responseKey} and {fragmentGroup} in {fragmentGroupedFieldSet}:
+      - Let {groupForResponseKey} be the record in {groupedFieldSet} for
+        {responseKey}.
+      - If {groupForResponseKey} is {undefined}, set the record in
+        {groupedFieldSet} for {responseKey} to {fragmentGroup}.
+      - Otherwise:
+        - Let {fieldGroupPriority} be equal to the {priority} entry on
+          {fragmentGroup}.
+        - Let {fragmentGroupPriority} be equal to the {priority} entry on
+          {fragmentGroup}.
+        - If {fragmentGroupPriority} is less than {fieldGroupPriority}, update
+          the {priority} entry on {fieldGroup} to {fragmentGroupPriority}.
+        - Let {fields} be the corresponding entry on {groupForResponseKey}.
+        - Let {fragmentFields} be equal to the {fields} entry on
+          {fragmentGroup}.
+        - For each {fragmentDeferredFragment} and
+          {fragmentListForDeferredFragment} in {fragmentFields}:
+          - Let {label} be the corresponding entry in
+            {fragmentDeferredFragment}.
+          - Let {deferredFragment} be the record in {deferredFragments} for
+            {label}.
+          - Let {listForDeferredFragment} be the record in {fields} for
+            {deferredFragment}.
+          - If {listForDeferredFragment} is {undefined}, set the record in
+            {fields} for {deferredFragment} to
+            {fragmentListForDeferredFragment}.
+          - Otherwise, append all items in {fragmentListForDeferredFragment} to
+            {listForDeferredFragment}.
 - Return {groupedFields}, {deferredGroupedFieldsList} and {visitedFragments}.
 
 Note: The steps in {CollectFields()} evaluating the `@skip` and `@include`
