Initialisation

Added the packages and files for the backend server

node_modules/graphql/utilities/valueFromAST.js

@@ -0,0 +1,197 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', {
+  value: true,
+});
+exports.valueFromAST = valueFromAST;
+
+var _inspect = require('../jsutils/inspect.js');
+
+var _invariant = require('../jsutils/invariant.js');
+
+var _keyMap = require('../jsutils/keyMap.js');
+
+var _kinds = require('../language/kinds.js');
+
+var _definition = require('../type/definition.js');
+
+/**
+ * Produces a JavaScript value given a GraphQL Value AST.
+ *
+ * A GraphQL type must be provided, which will be used to interpret different
+ * GraphQL Value literals.
+ *
+ * Returns `undefined` when the value could not be validly coerced according to
+ * the provided type.
+ *
+ * | GraphQL Value        | JSON Value    |
+ * | -------------------- | ------------- |
+ * | Input Object         | Object        |
+ * | List                 | Array         |
+ * | Boolean              | Boolean       |
+ * | String               | String        |
+ * | Int / Float          | Number        |
+ * | Enum Value           | Unknown       |
+ * | NullValue            | null          |
+ *
+ */
+function valueFromAST(valueNode, type, variables) {
+  if (!valueNode) {
+    // When there is no node, then there is also no value.
+    // Importantly, this is different from returning the value null.
+    return;
+  }
+
+  if (valueNode.kind === _kinds.Kind.VARIABLE) {
+    const variableName = valueNode.name.value;
+
+    if (variables == null || variables[variableName] === undefined) {
+      // No valid return value.
+      return;
+    }
+
+    const variableValue = variables[variableName];
+
+    if (variableValue === null && (0, _definition.isNonNullType)(type)) {
+      return; // Invalid: intentionally return no value.
+    } // Note: This does no further checking that this variable is correct.
+    // This assumes that this query has been validated and the variable
+    // usage here is of the correct type.
+
+    return variableValue;
+  }
+
+  if ((0, _definition.isNonNullType)(type)) {
+    if (valueNode.kind === _kinds.Kind.NULL) {
+      return; // Invalid: intentionally return no value.
+    }
+
+    return valueFromAST(valueNode, type.ofType, variables);
+  }
+
+  if (valueNode.kind === _kinds.Kind.NULL) {
+    // This is explicitly returning the value null.
+    return null;
+  }
+
+  if ((0, _definition.isListType)(type)) {
+    const itemType = type.ofType;
+
+    if (valueNode.kind === _kinds.Kind.LIST) {
+      const coercedValues = [];
+
+      for (const itemNode of valueNode.values) {
+        if (isMissingVariable(itemNode, variables)) {
+          // If an array contains a missing variable, it is either coerced to
+          // null or if the item type is non-null, it considered invalid.
+          if ((0, _definition.isNonNullType)(itemType)) {
+            return; // Invalid: intentionally return no value.
+          }
+
+          coercedValues.push(null);
+        } else {
+          const itemValue = valueFromAST(itemNode, itemType, variables);
+
+          if (itemValue === undefined) {
+            return; // Invalid: intentionally return no value.
+          }
+
+          coercedValues.push(itemValue);
+        }
+      }
+
+      return coercedValues;
+    }
+
+    const coercedValue = valueFromAST(valueNode, itemType, variables);
+
+    if (coercedValue === undefined) {
+      return; // Invalid: intentionally return no value.
+    }
+
+    return [coercedValue];
+  }
+
+  if ((0, _definition.isInputObjectType)(type)) {
+    if (valueNode.kind !== _kinds.Kind.OBJECT) {
+      return; // Invalid: intentionally return no value.
+    }
+
+    const coercedObj = Object.create(null);
+    const fieldNodes = (0, _keyMap.keyMap)(
+      valueNode.fields,
+      (field) => field.name.value,
+    );
+
+    for (const field of Object.values(type.getFields())) {
+      const fieldNode = fieldNodes[field.name];
+
+      if (!fieldNode || isMissingVariable(fieldNode.value, variables)) {
+        if (field.defaultValue !== undefined) {
+          coercedObj[field.name] = field.defaultValue;
+        } else if ((0, _definition.isNonNullType)(field.type)) {
+          return; // Invalid: intentionally return no value.
+        }
+
+        continue;
+      }
+
+      const fieldValue = valueFromAST(fieldNode.value, field.type, variables);
+
+      if (fieldValue === undefined) {
+        return; // Invalid: intentionally return no value.
+      }
+
+      coercedObj[field.name] = fieldValue;
+    }
+
+    if (type.isOneOf) {
+      const keys = Object.keys(coercedObj);
+
+      if (keys.length !== 1) {
+        return; // Invalid: not exactly one key, intentionally return no value.
+      }
+
+      if (coercedObj[keys[0]] === null) {
+        return; // Invalid: value not non-null, intentionally return no value.
+      }
+    }
+
+    return coercedObj;
+  }
+
+  if ((0, _definition.isLeafType)(type)) {
+    // Scalars and Enums fulfill parsing a literal value via parseLiteral().
+    // Invalid values represent a failure to parse correctly, in which case
+    // no value is returned.
+    let result;
+
+    try {
+      result = type.parseLiteral(valueNode, variables);
+    } catch (_error) {
+      return; // Invalid: intentionally return no value.
+    }
+
+    if (result === undefined) {
+      return; // Invalid: intentionally return no value.
+    }
+
+    return result;
+  }
+  /* c8 ignore next 3 */
+  // Not reachable, all possible input types have been considered.
+
+  false ||
+    (0, _invariant.invariant)(
+      false,
+      'Unexpected input type: ' + (0, _inspect.inspect)(type),
+    );
+} // Returns true if the provided valueNode is a variable which is not defined
+// in the set of variables.
+
+function isMissingVariable(valueNode, variables) {
+  return (
+    valueNode.kind === _kinds.Kind.VARIABLE &&
+    (variables == null || variables[valueNode.name.value] === undefined)
+  );
+}