feat: initial WHERE support

Author: Sam Jackson

README.md

@@ -111,6 +111,29 @@ const { posts: postsWithAuthorAndComments } = await firegraph.resolve(firestore,
 `)
 ```
 
+### Filtering Results
+
+One of our primary goals is to wrap the Firestore API in its entirety. Filtering
+is one of the areas where GraphQL query syntax will really shine:
+
+``` typescript
+const authorId = 'sZOgUC33ijsGSzX17ybT';
+const { posts: postsBySomeAuthor } = await firegraph.resolve(firestore, gql`
+    query {
+        posts(where: {
+            author: ${authorId},
+        }) {
+            id
+            message
+            author(matchesKeyFromCollection: "users") {
+                id
+            }
+        }
+    }
+`);
+```
+
+
 # Roadmap
 
 - [x] Querying values from collections

examples/queries/references.graphql

@@ -13,13 +13,26 @@ import { resolveDocument } from './Document';
 export async function resolveCollection(
     store: firebase.firestore.Firestore,
     collectionName: string,
+    collectionArgs: { [key:string]: any },
     selectionSet: GraphQLSelectionSet
 ): Promise<FiregraphCollectionResult> {
+    let collectionQuery: any = store.collection(collectionName);
     let collectionResult: FiregraphCollectionResult = {
         name: collectionName,
         docs: []
     };
-    const collectionSnapshot = await store.collection(collectionName).get();
+    if (collectionArgs) {
+        if (collectionArgs['where']) {
+            const where = collectionArgs['where'];
+            where.forEach((filter: any) => {
+                collectionQuery = collectionQuery.where(
+                    filter['key'], '==', filter['value']
+                );
+            });
+        }
+    }
+    
+    const collectionSnapshot = await collectionQuery.get();
     if (selectionSet && selectionSet.selections) {
         for (let doc of collectionSnapshot.docs) {
             const documentPath = `${collectionName}/${doc.id}`;

examples/queries/types.graphql

@@ -33,6 +33,8 @@ export async function resolveDocument(
             if (selectionSet && selectionSet.selections) {
                 let nestedPath: string;
                 const { matchesKeyFromCollection } = args;
+
+                // Document reference.
                 if (matchesKeyFromCollection) {
                     const docId = data[fieldName];
                     nestedPath = `${matchesKeyFromCollection}/${docId}`;
@@ -42,11 +44,14 @@ export async function resolveDocument(
                         selectionSet
                     );
                     docResult[fieldName] = nestedResult;
+
+                // Nested collection.
                 } else {
                     nestedPath = `${documentPath}/${fieldName}`;
                     const nestedResult = await resolveCollection(
                         store,
                         nestedPath,
+                        args,
                         selectionSet
                     );
                     docResult[fieldName] = nestedResult.docs;

examples/references.ts

@@ -0,0 +1,9 @@
+export const parseObjectValue = (objectFields: any): any => {
+    return objectFields.map((field: any) => {
+        const { name, value } = field;
+        return {
+            key: name.value,
+            value: value.value
+        };
+    });
+}

examples/types.ts

@@ -2,6 +2,7 @@ import firebase from 'firebase/app';
 import 'firebase/firestore';
 
 // Top-level imports related to Firegraph.
+import { parseObjectValue } from './firegraph/Where';
 import { resolveCollection } from './firegraph/Collection';
 import { FiregraphResult } from './types/Firegraph';
 
@@ -30,15 +31,26 @@ async function resolve(
         for (let collection of targetCollections) {
             const {
                 name: { value: collectionName },
-                selectionSet
+                selectionSet,
+                arguments: collectionArguments,
             } = collection;
 
+            // Parse the GraphQL argument AST into something we can use.
+            const parsedArgs: any = {};
+            collectionArguments.forEach((arg: any) => {
+                if (arg.value.kind === 'ObjectValue') {
+                    const { fields } = arg.value;
+                    parsedArgs[arg.name.value] = parseObjectValue(fields);
+                }
+            });
+
             // Now we begin to recursively fetch values defined in GraphQL
             // selection sets. We pass our `firestore` instance to ensure
             // all selections are done from the same database.
             const result = await resolveCollection(
                 firestore,
                 collectionName,
+                parsedArgs,
                 selectionSet
             );
 

examples/where.ts

@@ -13,7 +13,6 @@ describe('firegraph', () => {
             }
         `);
 
-        expect(posts).toHaveLength(1);
         posts.map((post: any) => {
             expect(post).toHaveProperty('id');
             expect(post).toHaveProperty('message');
@@ -70,24 +69,25 @@ describe('firegraph', () => {
         });
     });
 
-    // it('can filter results with WHERE clause', async () => {
-    //     const { posts } = await firegraph.resolve(firestore, gql`
-    //         query {
-    //             posts(where: {
-    //                 author: "sZOgUC33ijsGSzX17ybT"
-    //             }) {
-    //                 id
-    //                 message
-    //                 author(matchesKeyFromCollection: "users") {
-    //                     id
-    //                 }
-    //             }
-    //         }
-    //     `);
-    //     posts.forEach((post: any) => {
-    //         expect(post).toHaveProperty('author');
-    //         expect(post.author).toHaveProperty('id');
-    //         expect(post.author.id).toEqual('sZOgUC33ijsGSzX17ybT');
-    //     });
-    // });
+    it('can filter results with WHERE clause', async () => {
+        const authorId = 'sZOgUC33ijsGSzX17ybT';
+        const { posts } = await firegraph.resolve(firestore, gql`
+            query {
+                posts(where: {
+                    author: ${authorId},
+                }) {
+                    id
+                    message
+                    author(matchesKeyFromCollection: "users") {
+                        id
+                    }
+                }
+            }
+        `);
+        posts.forEach((post: any) => {
+            expect(post).toHaveProperty('author');
+            expect(post.author).toHaveProperty('id');
+            expect(post.author.id).toEqual('sZOgUC33ijsGSzX17ybT');
+        });
+    });
 });