feat: validation rule for defer/stream support

.changeset/red-coins-develop.md

@@ -0,0 +1,5 @@
+---
+'graphql-yoga': minor
+---
+
+bring in validation rules for defer stream graphql/graphql-js#3659

packages/graphql-yoga/__tests__/validations/defer-stream-directive-label.spec.ts

@@ -0,0 +1,169 @@
+import { DeferStreamDirectiveLabelRule } from '../../src/validations/defer-stream-directive-label.js'
+
+import { expectValidationErrors } from './harness.js'
+
+function expectErrors(queryStr: string) {
+  return expectValidationErrors(DeferStreamDirectiveLabelRule, queryStr)
+}
+
+function expectValid(queryStr: string) {
+  expectErrors(queryStr).toDeepEqual([])
+}
+
+describe('Validate: Defer/Stream directive on root field', () => {
+  it('Defer fragments with no label', () => {
+    expectValid(`
+      {
+        dog {
+          ...dogFragmentA @defer
+          ...dogFragmentB @defer
+        }
+      }
+      fragment dogFragmentA on Dog {
+        name
+      }
+      fragment dogFragmentB on Dog {
+        nickname
+      }
+    `)
+  })
+
+  it('Defer fragments, one with label, one without', () => {
+    expectValid(`
+      {
+        dog {
+          ...dogFragmentA @defer(label: "fragA")
+          ...dogFragmentB @defer
+        }
+      }
+      fragment dogFragmentA on Dog {
+        name
+      }
+      fragment dogFragmentB on Dog {
+        nickname
+      }
+    `)
+  })
+
+  it('Defer fragment with variable label', () => {
+    expectErrors(`
+    query($label: String) {
+      dog {
+        ...dogFragmentA @defer(label: $label)
+        ...dogFragmentB @defer(label: "fragA")
+      }
+    }
+    fragment dogFragmentA on Dog {
+      name
+    }
+    fragment dogFragmentB on Dog {
+      nickname
+    }
+    `).toDeepEqual([
+      {
+        message: 'Directive "defer"\'s label argument must be a static string.',
+        locations: [{ line: 4, column: 25 }],
+      },
+    ])
+  })
+
+  it('Defer fragments with different labels', () => {
+    expectValid(`
+    {
+      dog {
+        ...dogFragmentA @defer(label: "fragB")
+        ...dogFragmentB @defer(label: "fragA")
+      }
+    }
+    fragment dogFragmentA on Dog {
+      name
+    }
+    fragment dogFragmentB on Dog {
+      nickname
+    }
+    `)
+  })
+  it('Defer fragments with same label', () => {
+    expectErrors(`
+    {
+      dog {
+        ...dogFragmentA @defer(label: "fragA")
+        ...dogFragmentB @defer(label: "fragA")
+      }
+    }
+    fragment dogFragmentA on Dog {
+      name
+    }
+    fragment dogFragmentB on Dog {
+      nickname
+    }
+    `).toDeepEqual([
+      {
+        message: 'Defer/Stream directive label argument must be unique.',
+        locations: [
+          { line: 4, column: 25 },
+          { line: 5, column: 25 },
+        ],
+      },
+    ])
+  })
+  it('Defer and stream with no label', () => {
+    expectValid(`
+      {
+        dog {
+          ...dogFragment @defer
+        }
+        pets @stream(initialCount: 0) @stream {
+          name
+        }
+      }
+      fragment dogFragment on Dog {
+        name
+      }
+    `)
+  })
+  it('Stream with variable label', () => {
+    expectErrors(`
+      query ($label: String!) {
+        dog {
+          ...dogFragment @defer
+        }
+        pets @stream(initialCount: 0) @stream(label: $label) {
+          name
+        }
+      }
+      fragment dogFragment on Dog {
+        name
+      }
+      `).toDeepEqual([
+      {
+        message:
+          'Directive "stream"\'s label argument must be a static string.',
+        locations: [{ line: 6, column: 39 }],
+      },
+    ])
+  })
+  it('Defer and stream with the same label', () => {
+    expectErrors(`
+      {
+        dog {
+          ...dogFragment @defer(label: "MyLabel")
+        }
+        pets @stream(initialCount: 0) @stream(label: "MyLabel") {
+          name
+        }
+      }
+      fragment dogFragment on Dog {
+        name
+      }
+      `).toDeepEqual([
+      {
+        message: 'Defer/Stream directive label argument must be unique.',
+        locations: [
+          { line: 4, column: 26 },
+          { line: 6, column: 39 },
+        ],
+      },
+    ])
+  })
+})