push fixes

this has already helped us find some additional edge cases!

Author: yaacovCR

src/utilities/__tests__/coerceInputValue-test.ts

@@ -639,7 +639,7 @@ describe('coerceInputLiteral', () => {
     parser.expectToken(TokenKind.SOF);
     const variableValuesOrErrors = getVariableValues(
       new GraphQLSchema({}),
-      parser.parseVariableDefinitions(),
+      parser.parseVariableDefinitions() ?? [],
       inputs,
     );
     invariant(variableValuesOrErrors.variableValues !== undefined);
@@ -698,6 +698,15 @@ describe('coerceInputLiteral', () => {
       '~~~{ field: "value" }~~~',
     );
 
+    testWithVariables('', {}, '{ field: $var }', printScalar, '~~~{  }~~~');
+    testWithVariables(
+      '($var: String)',
+      {},
+      '{ field: $var }',
+      printScalar,
+      '~~~{  }~~~',
+    );
+
     const throwScalar = new GraphQLScalarType({
       name: 'ThrowScalar',
       parseConstLiteral() {

src/utilities/__tests__/replaceVariables-test.ts

@@ -24,7 +24,7 @@ function testVariables(variableDefs: string, inputs: ReadOnlyObjMap<unknown>) {
   parser.expectToken(TokenKind.SOF);
   const variableValuesOrErrors = getVariableValues(
     new GraphQLSchema({ types: [GraphQLInt] }),
-    parser.parseVariableDefinitions(),
+    parser.parseVariableDefinitions() ?? [],
     inputs,
   );
   invariant(variableValuesOrErrors.variableValues !== undefined);
@@ -60,9 +60,8 @@ describe('replaceVariables', () => {
 
     it('replaces missing Variables with null', () => {
       const ast = parseValue('$var');
-      expect(replaceVariables(ast, undefined)).to.deep.equal(
-        parseValue('null'),
-      );
+      const vars = testVariables('', {});
+      expect(replaceVariables(ast, vars)).to.deep.equal(parseValue('null'));
     });
 
     it('replaces missing Variables in lists with null', () => {

src/utilities/replaceVariables.ts

@@ -31,11 +31,11 @@ export function replaceVariables(
         ? fragmentVariableValues
         : variableValues;
 
-      if (scopedVariableValues == null) {
+      const scopedVariableSource = scopedVariableValues?.sources[varName];
+      if (scopedVariableSource == null) {
         return { kind: Kind.NULL };
       }
 
-      const scopedVariableSource = scopedVariableValues.sources[varName];
       if (scopedVariableSource.value === undefined) {
         const defaultValue = scopedVariableSource.signature.defaultValue;
         if (defaultValue !== undefined) {