feat(hooks): hook for individual enum value (#25)

packages/graphql-build/__tests__/__snapshots__/enum.test.js.snap

@@ -0,0 +1,34 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`generated schema 1`] = `
+"enum MyEnum {
+  ONE @deprecated(reason: \\"We no longer support numbers smaller than PI\\")
+  TWO @deprecated(reason: \\"We no longer support numbers smaller than PI\\")
+  THREE @deprecated(reason: \\"We no longer support numbers smaller than PI\\")
+  FOUR
+}
+
+# An object with a globally unique \`ID\`.
+interface Node {
+  # A globally unique identifier. Can be used in various places throughout the system to identify this single value.
+  nodeId: ID!
+}
+
+# The root query type which gives access points into the data universe.
+type Query implements Node {
+  # Exposes the root query type nested one level down. This is helpful for Relay 1
+  # which can only query top level fields if they are in a particular form.
+  query: Query!
+
+  # The root query type must be a \`Node\` to work well with Relay 1 mutations. This just resolves to \`query\`.
+  nodeId: ID!
+
+  # Fetches an object given its globally unique \`ID\`.
+  node(
+    # The globally unique \`ID\`.
+    nodeId: ID!
+  ): Node
+  enum: MyEnum
+}
+"
+`;

packages/graphql-build/__tests__/enum.test.js

@@ -0,0 +1,88 @@
+const {
+  graphql,
+  GraphQLObjectType,
+  GraphQLEnumType,
+  GraphQLInt,
+  GraphQLString,
+  GraphQLNonNull,
+  GraphQLList,
+} = require("graphql");
+const { printSchema } = require("graphql/utilities");
+const { buildSchema, defaultPlugins, MutationPlugin } = require("../");
+
+const base64 = str => new Buffer(String(str)).toString("base64");
+const base64Decode = str => new Buffer(String(str), "base64").toString("utf8");
+
+const dummyData = [
+  { ID: "foo", CAPS: "FOO" },
+  { ID: "bar", CAPS: "BAR" },
+  { ID: "baz", CAPS: "BAZ" },
+  { ID: "qux", CAPS: "QUX" },
+];
+
+const compare = (a, b, ascending) => {
+  if (a === b) return 0;
+  if (ascending) {
+    return a > b ? 1 : -1;
+  } else {
+    return a < b ? 1 : -1;
+  }
+};
+
+function EnumPlugin(builder) {
+  builder.hook(
+    "GraphQLObjectType:fields",
+    (fields, { extend, newWithHooks }, { scope: { isRootQuery } }) => {
+      if (!isRootQuery) {
+        return fields;
+      }
+      const MyEnum = newWithHooks(
+        GraphQLEnumType,
+        {
+          name: "MyEnum",
+          values: {
+            ONE: { value: 1 },
+            TWO: { value: 2 },
+            THREE: { value: 3 },
+          },
+        },
+        {
+          isMyEnum: true,
+        }
+      );
+      return extend(fields, {
+        enum: {
+          type: MyEnum,
+        },
+      });
+    }
+  );
+  builder.hook(
+    "GraphQLEnumType:values",
+    (values, { extend }, { scope: { isMyEnum } }) => {
+      if (!isMyEnum) {
+        return values;
+      }
+      return extend(values, {
+        FOUR: { value: 4 },
+      });
+    }
+  );
+  builder.hook(
+    "GraphQLEnumType:values:value",
+    (value, { extend }, { scope: { isMyEnum } }) => {
+      if (isMyEnum && value.value < 4) {
+        return extend(value, {
+          deprecationReason: "We no longer support numbers smaller than PI",
+        });
+      } else {
+        return value;
+      }
+    }
+  );
+}
+
+test("generated schema", async () => {
+  const schema = await buildSchema([...defaultPlugins, EnumPlugin]);
+  expect(printSchema(schema)).toMatchSnapshot();
+});

packages/graphql-build/src/SchemaBuilder.js

@@ -209,8 +209,10 @@ class SchemaBuilder extends EventEmitter {
       // execute, the following hooks:
       // - 'GraphQLEnumType' to add any root-level attributes, e.g. add a description
       // - 'GraphQLEnumType:values' to add additional values
+      // - 'GraphQLEnumType:values:value' to change an individual value
       GraphQLEnumType: [],
       "GraphQLEnumType:values": [],
+      "GraphQLEnumType:values:value": [],
     };
   }
 

packages/graphql-build/src/makeNewBuild.js

@@ -514,6 +514,21 @@ export default function makeNewBuild(builder: SchemaBuilder): Build {
           },
           `|${newSpec.name}`
         );
+        const values = newSpec.values;
+        newSpec.values = Object.keys(values).reduce((memo, valueKey) => {
+          const value = values[valueKey];
+          const newValue = builder.applyHooks(
+            this,
+            "GraphQLEnumType:values:value",
+            value,
+            {
+              scope,
+            },
+            `|${newSpec.name}|${valueKey}`
+          );
+          memo[valueKey] = newValue;
+          return memo;
+        }, {});
       }
       const finalSpec: ConfigType = newSpec;