Clearer error messages

This adds clearer errors for incorrect variables.

Does not wrap printed values in quotes, to avoid ambiguity with strings.

Author: leebyron

src/execution/__tests__/variables.js

@@ -231,7 +231,7 @@ describe('Execute: Handles inputs', () => {
         expect(caughtError).to.containSubset({
           locations: [ { line: 2, column: 17 } ],
           message:
-            'Variable $input expected value of type TestInputObject but ' +
+            'Variable "$input" expected value of type "TestInputObject" but ' +
             'got: {"a":"foo","b":"bar","c":null}.'
         });
       });
@@ -249,7 +249,7 @@ describe('Execute: Handles inputs', () => {
         expect(caughtError).to.containSubset({
           locations: [ { line: 2, column: 17 } ],
           message:
-            'Variable $input expected value of type TestInputObject but ' +
+            'Variable "$input" expected value of type "TestInputObject" but ' +
             'got: "foo bar".'
         });
       });
@@ -267,7 +267,7 @@ describe('Execute: Handles inputs', () => {
         expect(caughtError).to.containSubset({
           locations: [ { line: 2, column: 17 } ],
           message:
-            'Variable $input expected value of type TestInputObject but ' +
+            'Variable "$input" expected value of type "TestInputObject" but ' +
             'got: {"a":"foo","b":"bar"}.'
         });
       });
@@ -285,7 +285,7 @@ describe('Execute: Handles inputs', () => {
         expect(caughtError).to.containSubset({
           locations: [ { line: 2, column: 17 } ],
           message:
-            'Variable $input expected value of type TestInputObject but ' +
+            'Variable "$input" expected value of type "TestInputObject" but ' +
             'got: {"a":"foo","b":"bar","c":"baz","d":"dog"}.'
         });
       });
@@ -407,7 +407,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 31 } ],
         message:
-          'Variable $value expected value of type String! but got: undefined.'
+          'Variable "$value" of required type "String!" was not provided.'
       });
     });
 
@@ -429,7 +429,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 31 } ],
         message:
-          'Variable $value expected value of type String! but got: null.'
+          'Variable "$value" of required type "String!" was not provided.'
       });
     });
 
@@ -551,7 +551,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 17 } ],
         message:
-          'Variable $input expected value of type [String]! but got: null.'
+          'Variable "$input" of required type "[String]!" was not provided.'
       });
     });
 
@@ -642,7 +642,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 17 } ],
         message:
-          'Variable $input expected value of type [String!] but got: ' +
+          'Variable "$input" expected value of type "[String!]" but got: ' +
           '["A",null,"B"].'
       });
     });
@@ -665,7 +665,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 17 } ],
         message:
-          'Variable $input expected value of type [String!]! but got: null.'
+          'Variable "$input" of required type "[String!]!" was not provided.'
       });
     });
 
@@ -705,7 +705,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 17 } ],
         message:
-          'Variable $input expected value of type [String!]! but got: ' +
+          'Variable "$input" expected value of type "[String!]!" but got: ' +
           '["A",null,"B"].'
       });
     });
@@ -729,7 +729,7 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 17 } ],
         message:
-          'Variable $input expected value of type TestType! which cannot ' +
+          'Variable "$input" expected value of type "TestType!" which cannot ' +
           'be used as an input type.'
       });
     });
@@ -753,8 +753,8 @@ describe('Execute: Handles inputs', () => {
       expect(caughtError).to.containSubset({
         locations: [ { line: 2, column: 17 } ],
         message:
-          'Variable $input expected value of type UnknownType! which cannot ' +
-          'be used as an input type.'
+          'Variable "$input" expected value of type "UnknownType!" which ' +
+          'cannot be used as an input type.'
       });
     });
 

src/execution/values.js

@@ -85,10 +85,11 @@ function getVariableValue(
   input: ?any
 ): any {
   var type = typeFromAST(schema, definitionAST.type);
+  var variable = definitionAST.variable;
   if (!type || !isInputType(type)) {
     throw new GraphQLError(
-      `Variable $${definitionAST.variable.name.value} expected value of type ` +
-      `${print(definitionAST.type)} which cannot be used as an input type.`,
+      `Variable "$${variable.name.value}" expected value of type ` +
+      `"${print(definitionAST.type)}" which cannot be used as an input type.`,
       [ definitionAST ]
     );
   }
@@ -101,9 +102,16 @@ function getVariableValue(
     }
     return coerceValue(type, input);
   }
+  if (isNullish(input)) {
+    throw new GraphQLError(
+      `Variable "$${variable.name.value}" of required type ` +
+      `"${print(definitionAST.type)}" was not provided.`,
+      [ definitionAST ]
+    );
+  }
   throw new GraphQLError(
-    `Variable $${definitionAST.variable.name.value} expected value of type ` +
-    `${print(definitionAST.type)} but got: ${JSON.stringify(input)}.`,
+    `Variable "$${variable.name.value}" expected value of type ` +
+    `"${print(definitionAST.type)}" but got: ${JSON.stringify(input)}.`,
     [ definitionAST ]
   );
 }

src/validation/rules/ArgumentsOfCorrectType.js

@@ -15,7 +15,7 @@ import { isValidLiteralValue } from '../../utilities/isValidLiteralValue';
 
 
 export function badValueMessage(argName: any, type: any, value: any): string {
-  return `Argument "${argName}" expected type "${type}" but got: "${value}".`;
+  return `Argument "${argName}" expected type "${type}" but got: ${value}.`;
 }
 
 /**

src/validation/rules/DefaultValuesOfCorrectType.js

@@ -30,7 +30,7 @@ export function badValueForDefaultArgMessage(
   value: any
 ): string {
   return `Variable "$${varName}" of type "${type}" has invalid default ` +
-    `value: "${value}".`;
+    `value: ${value}.`;
 }
 
 /**