Input Value Validation

Factors out input validation to reusable functions:

* Introduces `validateInputLiteral` by extracting this behavior from `ValuesOfCorrectTypeRule`.
* Introduces `validateInputValue` by extracting this behavior from `coerceInputValue`
* Simplifies `coerceInputValue` to return early on validation error
* Unifies error reporting between `validateInputValue` and `validateInputLiteral`, causing some error message strings to change, but error data (eg locations) are preserved.

These two parallel functions will be used to validate default values in #3049

Potentially breaking if you rely on the existing behavior of `coerceInputValue` to call a callback function, as the call signature has changed. GraphQL behavior should not change, though error messages are now slightly different.

Author: leebyron

src/execution/__tests__/nonnull-test.ts

@@ -643,7 +643,7 @@ describe('Execute: handles non-nullable types', () => {
         errors: [
           {
             message:
-              'Argument Query.withNonNullArg(cannotBeNull:) of non-null type String! must not be null.',
+              'Argument Query.withNonNullArg(cannotBeNull:) has invalid value: Expected value of non-null type String! not to be null.',
             locations: [{ line: 3, column: 42 }],
             path: ['withNonNullArg'],
           },
@@ -673,7 +673,7 @@ describe('Execute: handles non-nullable types', () => {
         errors: [
           {
             message:
-              'Argument Query.withNonNullArg(cannotBeNull:) of required type String! was provided the variable "$testVar" which was not provided a runtime value.',
+              'Argument Query.withNonNullArg(cannotBeNull:) has invalid value: Expected variable "$testVar" provided to type String! to provide a runtime value.',
             locations: [{ line: 3, column: 42 }],
             path: ['withNonNullArg'],
           },
@@ -701,7 +701,7 @@ describe('Execute: handles non-nullable types', () => {
         errors: [
           {
             message:
-              'Argument Query.withNonNullArg(cannotBeNull:) of non-null type String! must not be null.',
+              'Argument Query.withNonNullArg(cannotBeNull:) has invalid value: Expected variable "$testVar" provided to non-null type String! not to be null.',
             locations: [{ line: 3, column: 43 }],
             path: ['withNonNullArg'],
           },

src/execution/__tests__/variables-test.ts

@@ -203,7 +203,7 @@ describe('Execute: Handles inputs', () => {
           errors: [
             {
               message:
-                'Argument TestType.fieldWithObjectInput(input:) of type TestInputObject has invalid value ["foo", "bar", "baz"].',
+                'Argument TestType.fieldWithObjectInput(input:) has invalid value: Expected value of type TestInputObject to be an object, found: ["foo", "bar", "baz"].',
               path: ['fieldWithObjectInput'],
               locations: [{ line: 3, column: 41 }],
             },
@@ -373,7 +373,7 @@ describe('Execute: Handles inputs', () => {
           errors: [
             {
               message:
-                'Variable "$input" got invalid value null at "input.c"; Expected non-nullable type "String!" not to be null.',
+                'Variable "$input" has invalid value at .c: Expected value of non-null type String! not to be null.',
               locations: [{ line: 2, column: 16 }],
             },
           ],
@@ -387,7 +387,7 @@ describe('Execute: Handles inputs', () => {
           errors: [
             {
               message:
-                'Variable "$input" got invalid value "foo bar"; Expected type "TestInputObject" to be an object.',
+                'Variable "$input" has invalid value: Expected value of type TestInputObject to be an object, found: "foo bar".',
               locations: [{ line: 2, column: 16 }],
             },
           ],
@@ -401,7 +401,7 @@ describe('Execute: Handles inputs', () => {
           errors: [
             {
               message:
-                'Variable "$input" got invalid value { a: "foo", b: "bar" }; Field "c" of required type "String!" was not provided.',
+                'Variable "$input" has invalid value: Expected value of type TestInputObject to include required field "c", found: { a: "foo", b: "bar" }.',
               locations: [{ line: 2, column: 16 }],
             },
           ],
@@ -420,12 +420,12 @@ describe('Execute: Handles inputs', () => {
           errors: [
             {
               message:
-                'Variable "$input" got invalid value { a: "foo" } at "input.na"; Field "c" of required type "String!" was not provided.',
+                'Variable "$input" has invalid value at .na: Expected value of type TestInputObject to include required field "c", found: { a: "foo" }.',
               locations: [{ line: 2, column: 18 }],
             },
             {
               message:
-                'Variable "$input" got invalid value { na: { a: "foo" } }; Field "nb" of required type "String!" was not provided.',
+                'Variable "$input" has invalid value: Expected value of type TestNestedInputObject to include required field "nb", found: { na: { a: "foo" } }.',
               locations: [{ line: 2, column: 18 }],
             },
           ],
@@ -442,7 +442,7 @@ describe('Execute: Handles inputs', () => {
           errors: [
             {
               message:
-                'Variable "$input" got invalid value { a: "foo", b: "bar", c: "baz", extra: "dog" }; Field "extra" is not defined by type "TestInputObject".',
+                'Variable "$input" has invalid value: Expected value of type TestInputObject not to include unknown field "extra", found: { a: "foo", b: "bar", c: "baz", extra: "dog" }.',
               locations: [{ line: 2, column: 16 }],
             },
           ],
@@ -617,7 +617,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$value" of required type String! was not provided.',
+              'Variable "$value" has invalid value: Expected a value of non-null type String! to be provided.',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -636,7 +636,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$value" of non-null type String! must not be null.',
+              'Variable "$value" has invalid value: Expected value of non-null type String! not to be null.',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -702,7 +702,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$value" got invalid value [1, 2, 3]; String cannot represent a non string value: [1, 2, 3]',
+              'Variable "$value" has invalid value: String cannot represent a non string value: [1, 2, 3]',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -730,7 +730,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Argument TestType.fieldWithNonNullableStringInput(input:) of required type String! was provided the variable "$foo" which was not provided a runtime value.',
+              'Argument TestType.fieldWithNonNullableStringInput(input:) has invalid value: Expected variable "$foo" provided to type String! to provide a runtime value.',
             locations: [{ line: 3, column: 50 }],
             path: ['fieldWithNonNullableStringInput'],
           },
@@ -785,7 +785,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$input" of non-null type [String]! must not be null.',
+              'Variable "$input" has invalid value: Expected value of non-null type [String]! not to be null.',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -848,7 +848,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$input" got invalid value null at "input[1]"; Expected non-nullable type "String!" not to be null.',
+              'Variable "$input" has invalid value at [1]: Expected value of non-null type String! not to be null.',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -867,7 +867,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$input" of non-null type [String!]! must not be null.',
+              'Variable "$input" has invalid value: Expected value of non-null type [String!]! not to be null.',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -897,7 +897,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Variable "$input" got invalid value null at "input[1]"; Expected non-nullable type "String!" not to be null.',
+              'Variable "$input" has invalid value at [1]: Expected value of non-null type String! not to be null.',
             locations: [{ line: 2, column: 16 }],
           },
         ],
@@ -982,7 +982,7 @@ describe('Execute: Handles inputs', () => {
         errors: [
           {
             message:
-              'Argument TestType.fieldWithDefaultArgumentValue(input:) of type String has invalid value WRONG_TYPE.',
+              'Argument TestType.fieldWithDefaultArgumentValue(input:) has invalid value: String cannot represent a non string value: WRONG_TYPE',
             locations: [{ line: 3, column: 48 }],
             path: ['fieldWithDefaultArgumentValue'],
           },
@@ -1022,7 +1022,7 @@ describe('Execute: Handles inputs', () => {
 
     function invalidValueError(value: number, index: number) {
       return {
-        message: `Variable "$input" got invalid value ${value} at "input[${index}]"; String cannot represent a non string value: ${value}`,
+        message: `Variable "$input" has invalid value at [${index}]: String cannot represent a non string value: ${value}`,
         locations: [{ line: 2, column: 14 }],
       };
     }

src/execution/values.ts

@@ -1,7 +1,7 @@
 import type { ObjMap, ReadOnlyObjMap } from '../jsutils/ObjMap';
 import type { Maybe } from '../jsutils/Maybe';
 import { keyMap } from '../jsutils/keyMap';
-import { inspect } from '../jsutils/inspect';
+import { invariant } from '../jsutils/invariant';
 import { printPathArray } from '../jsutils/printPathArray';
 
 import { GraphQLError } from '../error/GraphQLError';
@@ -17,14 +17,22 @@ import { print } from '../language/printer';
 import type { GraphQLSchema } from '../type/schema';
 import type { GraphQLInputType, GraphQLField } from '../type/definition';
 import type { GraphQLDirective } from '../type/directives';
-import { isInputType, isNonNullType } from '../type/definition';
+import {
+  isInputType,
+  isNonNullType,
+  isRequiredArgument,
+} from '../type/definition';
 
 import { typeFromAST } from '../utilities/typeFromAST';
 import {
   coerceInputValue,
   coerceInputLiteral,
   coerceDefaultValue,
 } from '../utilities/coerceInputValue';
+import {
+  validateInputValue,
+  validateInputLiteral,
+} from '../utilities/validateInputValue';
 
 export interface VariableValues {
   readonly sources: ReadOnlyObjMap<VariableValueSource>;
@@ -109,59 +117,38 @@ function coerceVariableValues(
       continue;
     }
 
-    if (!hasOwnProperty(inputs, varName)) {
-      const defaultValue = varDefNode.defaultValue;
-      if (defaultValue) {
-        sources[varName] = {
-          variable: varDefNode,
-          type: varType,
-          value: undefined,
-        };
-        coerced[varName] = coerceInputLiteral(defaultValue, varType);
-      } else if (isNonNullType(varType)) {
-        onError(
-          new GraphQLError(
-            `Variable "$${varName}" of required type ${varType} was not provided.`,
-            varDefNode,
-          ),
-        );
-      }
-      continue;
-    }
+    const value = hasOwnProperty(inputs, varName) ? inputs[varName] : undefined;
+    sources[varName] = { variable: varDefNode, type: varType, value };
 
-    const value = inputs[varName];
-    if (value === null && isNonNullType(varType)) {
-      onError(
-        new GraphQLError(
-          `Variable "$${varName}" of non-null type ${varType} must not be null.`,
-          varDefNode,
-        ),
-      );
-      continue;
+    if (value === undefined) {
+      if (varDefNode.defaultValue) {
+        coerced[varName] = coerceInputLiteral(varDefNode.defaultValue, varType);
+        continue;
+      } else if (!isNonNullType(varType)) {
+        // Non-provided values for nullable variables are omitted.
+        continue;
+      }
     }
 
-    sources[varName] = { variable: varDefNode, type: varType, value };
-    coerced[varName] = coerceInputValue(
-      value,
-      varType,
-      (path, invalidValue, error) => {
-        let prefix =
-          `Variable "$${varName}" got invalid value ` + inspect(invalidValue);
-        if (path.length > 0) {
-          prefix += ` at "${varName}${printPathArray(path)}"`;
-        }
+    const coercedValue = coerceInputValue(value, varType);
+    if (coercedValue !== undefined) {
+      coerced[varName] = coercedValue;
+    } else {
+      validateInputValue(value, varType, (error, path) => {
         onError(
           new GraphQLError(
-            prefix + '; ' + error.message,
+            `Variable "$${varName}" has invalid value${printPathArray(path)}: ${
+              error.message
+            }`,
             varDefNode,
             undefined,
             undefined,
             undefined,
             error.originalError,
           ),
         );
-      },
-    );
+      });
+    }
   }
 
   return { sources, coerced };
@@ -193,65 +180,52 @@ export function getArgumentValues(
     const argType = argDef.type;
     const argumentNode = argNodeMap[name];
 
-    if (!argumentNode) {
+    if (!argumentNode && isRequiredArgument(argDef)) {
+      // Note: ProvidedRequiredArgumentsRule validation should catch this before
+      // execution. This is a runtime check to ensure execution does not
+      // continue with an invalid argument value.
+      throw new GraphQLError(
+        `Argument ${argDef} of required type ${argType} was not provided.`,
+        node,
+      );
+    }
+
+    // Variables without a value are treated as if no argument was provided if
+    // the argument is not required.
+    if (
+      !argumentNode ||
+      (argumentNode.value.kind === Kind.VARIABLE &&
+        variableValues?.coerced[argumentNode.value.name.value] === undefined &&
+        !isRequiredArgument(argDef))
+    ) {
       if (argDef.defaultValue) {
         coercedValues[name] = coerceDefaultValue(
           argDef.defaultValue,
           argDef.type,
         );
-      } else if (isNonNullType(argType)) {
-        throw new GraphQLError(
-          `Argument ${argDef} of required type ${argType} was not provided.`,
-          node,
-        );
       }
       continue;
     }
 
     const valueNode = argumentNode.value;
-    let isNull = valueNode.kind === Kind.NULL;
-
-    if (valueNode.kind === Kind.VARIABLE) {
-      const variableName = valueNode.name.value;
-      if (
-        variableValues == null ||
-        variableValues.coerced[variableName] === undefined
-      ) {
-        if (argDef.defaultValue) {
-          coercedValues[name] = coerceDefaultValue(
-            argDef.defaultValue,
-            argDef.type,
-          );
-        } else if (isNonNullType(argType)) {
-          throw new GraphQLError(
-            `Argument ${argDef} of required type ${argType} ` +
-              `was provided the variable "$${variableName}" which was not provided a runtime value.`,
-            valueNode,
-          );
-        }
-        continue;
-      }
-      isNull = variableValues.coerced[variableName] == null;
-    }
-
-    if (isNull && isNonNullType(argType)) {
-      throw new GraphQLError(
-        `Argument ${argDef} of non-null type ${argType} must not be null.`,
-        valueNode,
-      );
-    }
-
     const coercedValue = coerceInputLiteral(valueNode, argType, variableValues);
     if (coercedValue === undefined) {
       // Note: ValuesOfCorrectTypeRule validation should catch this before
       // execution. This is a runtime check to ensure execution does not
       // continue with an invalid argument value.
-      throw new GraphQLError(
-        `Argument ${argDef} of type ${argType} has invalid value ${print(
-          valueNode,
-        )}.`,
+      validateInputLiteral(
         valueNode,
+        argType,
+        variableValues,
+        (error, path) => {
+          error.message = `Argument ${argDef} has invalid value${printPathArray(
+            path,
+          )}: ${error.message}`;
+          throw error;
+        },
       );
+      // istanbul ignore next (validateInputLiteral should throw)
+      invariant(false, 'Invalid argument');
     }
     coercedValues[name] = coercedValue;
   }