Merge branch 'master' into conflict

docs/graphql-migrations/db-design.md

@@ -342,6 +342,26 @@ type Note {
 }
 ```
 
+### Rename
+
+Table or columns can be renamed using the `@db(oldNames: ['old'])` annotation as shown below:
+
+```graphql
+"""
+@db(oldNames: ['task'])
+@model
+"""
+type Note {
+  id: ID!
+  """
+  @db(oldNames: ['text'])
+  """
+  title: String!
+}
+```
+
+This will rename the `text` to `title` and the table name to `note` without data loss. 
+
 ### Ignore a field 
 
 Sometimes our business model can contain more fields and some of these fields may only be there for representation purposes.

docs/graphql-migrations/plugins.md

@@ -4,4 +4,128 @@ title: GraphQL Migrations Plugins
 sidebar_label: Plugins
 ---
 
-## TODO
+# Custom logic with Plugins
+
+It's possible to write custom queries to be executed during migrations using Plugins.
+
+Currently a plugin can only declare tap on the Writer system, with the `write` and `tap` methods:
+
+```ts
+import { MigratePlugin, WriteParams } from 'graphql-migrations'
+
+class MyPlugin extends MigratePlugin {
+  write ({ tap }: WriteParams) {
+    tap('op-type', 'before', (op: any, transaction: any) => {
+      // or 'after'
+    })
+
+    return true;
+  }
+}
+```
+
+The arguments are:
+
+- `operation: string`, can be one of the following:
+  - `table.create`
+  - `table.rename`
+  - `table.comment.set`
+  - `table.drop`
+  - `table.index.create`
+  - `table.index.drop`
+  - `table.primary.set`
+  - `table.primary.drop`
+  - `table.unique.create`
+  - `table.unique.drop`
+  - `table.foreign.create`
+  - `table.foreign.drop`
+  - `column.create`
+  - `column.rename`
+  - `column.alter`
+  - `column.drop`
+- `type: 'before' | 'after'`
+- `callback: function` which get those parameters:
+  - `operation`: the operation object (see [Operation.ts](https://github.com/aerogear/graphback/blob/master/packages/graphql-migrations/src/diff/Operation.ts))
+  - `transaction`: the [Knex SQL transaction](http://knexjs.org/#Transactions)
+
+Then, instantiate the plugin in the `plugins` option array of the `migrateDB` method.
+
+For example, let's say we have the following schema:
+
+```graphql
+"""
+@model
+"""
+type User {
+  id: ID!
+  fname: String
+  lname: String
+}
+```
+
+Now we want to migrate the `user` table from two columns `fname` and `lname` into one:
+
+```ts
+fullname = fname + ' ' + lname
+```
+
+Here is the example code to achieve this:
+
+```ts
+import { migrateDB, MigratePlugin, WriteParams } from 'graphql-migrations';
+
+const schema = `
+"""
+@model
+"""
+type User {
+  id: ID!
+
+  """
+  db(oldNames: ['lname'])
+  """ 
+  fullname: String
+}
+`;
+
+class MyPlugin implements MigratePlugin {
+  write ({ tap }: WriteParams) {
+    tap('column.drop', 'before', async (op: any, transaction: any) => {
+      // Check the table and column
+      if (op.table === 'user' && op.column === 'fname') {
+        // Update the users lname with fname + ' ' + lname
+        const users = await transaction
+          .select('id', 'fname', 'lname')
+          .from('user');
+        for (const user of users) {
+          await transaction('user')
+            .where({ id: user.id })
+            .update({
+              lname: `${user.fname} ${user.lname}`
+            })
+        }
+      }
+    })
+
+    return true;
+  }
+}
+
+const dbConfig = {
+    // Knex database configuration
+}
+
+migrateDB(dbConfig, schema, {
+  plugins: [
+    new MyPlugin(),
+  ]
+})
+```
+
+The above code does the following:
+
+- Remove the `fname` field from the schema.
+- Rename `lname` to `fullname` in the schema.
+- Annotate the `fullname` field to indicate it's the new name of `lname`.
+- We declare a plugin that tap into the `column.drop` write operation.
+- In this hook, we read the users and update each one of them to merge the two columns into `lname` before the `fname` column is dropped.

package.json

@@ -17,7 +17,7 @@
     "eslint-plugin-jsx-a11y": "6.3.1",
     "eslint-plugin-no-null": "1.0.2",
     "eslint-plugin-react": "7.20.3",
-    "eslint-plugin-react-hooks": "4.0.5",
+    "eslint-plugin-react-hooks": "4.0.6",
     "husky": "4.2.5",
     "lerna": "3.22.1",
     "npm-run-all": "4.1.5",

packages/graphback-cli/package.json

@@ -46,7 +46,7 @@
     "chalk": "2.4.2",
     "chokidar": "3.4.0",
     "debounce": "1.2.0",
-    "execa": "4.0.2",
+    "execa": "4.0.3",
     "figlet": "1.4.0",
     "glob": "7.1.6",
     "graphback": "0.14.0-alpha4",

packages/graphback/package.json

@@ -39,7 +39,7 @@
     "@graphql-tools/merge": "6.0.10",
     "glob": "7.1.6",
     "graphql-subscriptions": "1.1.0",
-    "pg": "8.2.1",
+    "pg": "8.2.2",
     "pino": "6.3.2",
     "tslib": "2.0.0"
   },

packages/graphql-migrations/package.json

@@ -36,7 +36,7 @@
     "graphql": "15.3.0",
     "graphql-tools": "6.0.10",
     "jest": "26.1.0",
-    "pg": "8.2.1",
+    "pg": "8.2.2",
     "rimraf": "3.0.2",
     "sqlite3": "4.2.0",
     "ts-node": "8.10.2",