From c3883e01c01b83cf5938de9bebf2dd68f4861364 Mon Sep 17 00:00:00 2001
From: Tim Leslie <timl@thinkmill.com.au>
Date: Tue, 21 Jul 2020 12:01:59 +1000
Subject: [PATCH] Change many-relationship graphQL type to [Item!]! (#3261)

---
 .changeset/wet-masks-sort.md                  |  9 +++++++
 .../src/types/Relationship/Implementation.js  |  4 +---
 .../Relationship/tests/implementation.test.js | 24 ++++++++++++++-----
 3 files changed, 28 insertions(+), 9 deletions(-)
 create mode 100644 .changeset/wet-masks-sort.md

diff --git a/.changeset/wet-masks-sort.md b/.changeset/wet-masks-sort.md
new file mode 100644
index 00000000000..d4996c4e650
--- /dev/null
+++ b/.changeset/wet-masks-sort.md
@@ -0,0 +1,9 @@
+---
+'@keystonejs/fields': major
+---
+
+`many` relationships now have a GraphQL type of `[Item!]!`, rather than `[Item]`.
+
+The old type of `[Item]` implied that the relationship field could return `null`, or that some of the items it returned could be `null`. In practice, neither of these things ever happened. The new type better reflects this reality.
+
+The filter argument `{path}_is_null` has also been removed for `many` relationships, as it does not apply to a non-null array type.
diff --git a/packages/fields/src/types/Relationship/Implementation.js b/packages/fields/src/types/Relationship/Implementation.js
index 43c6a9fb6f2..2ebd7cc482f 100644
--- a/packages/fields/src/types/Relationship/Implementation.js
+++ b/packages/fields/src/types/Relationship/Implementation.js
@@ -60,7 +60,7 @@ export class Relationship extends Implementation {
     if (this.many) {
       const filterArgs = refList.getGraphqlFilterFragment().join('\n');
       return [
-        `${this.path}(${filterArgs}): [${refList.gqlNames.outputTypeName}]`,
+        `${this.path}(${filterArgs}): [${refList.gqlNames.outputTypeName}!]!`,
         this.withMeta ? `_${this.path}Meta(${filterArgs}): _QueryMeta` : '',
       ];
     }
@@ -89,8 +89,6 @@ export class Relationship extends Implementation {
         ${this.path}_some: ${refList.gqlNames.whereInputName}`,
         `""" condition must be false for all nodes """
         ${this.path}_none: ${refList.gqlNames.whereInputName}`,
-        `""" is the relation field null """
-        ${this.path}_is_null: Boolean`,
       ];
     } else {
       return [`${this.path}: ${refList.gqlNames.whereInputName}`, `${this.path}_is_null: Boolean`];
diff --git a/packages/fields/src/types/Relationship/tests/implementation.test.js b/packages/fields/src/types/Relationship/tests/implementation.test.js
index 8b81b39e503..868c13ce4c0 100644
--- a/packages/fields/src/types/Relationship/tests/implementation.test.js
+++ b/packages/fields/src/types/Relationship/tests/implementation.test.js
@@ -296,10 +296,16 @@ describe('Type Generation', () => {
               },
               arguments: mockFilterAST,
               type: {
-                kind: 'ListType',
+                kind: 'NonNullType',
                 type: {
-                  name: {
-                    value: 'Zip',
+                  kind: 'ListType',
+                  type: {
+                    kind: 'NonNullType',
+                    type: {
+                      name: {
+                        value: 'Zip',
+                      },
+                    },
                   },
                 },
               },
@@ -354,10 +360,16 @@ describe('Type Generation', () => {
               },
               arguments: mockFilterAST,
               type: {
-                kind: 'ListType',
+                kind: 'NonNullType',
                 type: {
-                  name: {
-                    value: 'Zip',
+                  kind: 'ListType',
+                  type: {
+                    kind: 'NonNullType',
+                    type: {
+                      name: {
+                        value: 'Zip',
+                      },
+                    },
                   },
                 },
               },