feat(pg-connection-string): ClientConfig helper functions

Two new functions are introduced to make it easy for TypeScript
users to use a PostgresSQL connection string with pg Client.

Fixes brianc#2280

packages/pg-connection-string/README.md

@@ -35,6 +35,27 @@ The resulting config contains a subset of the following properties:
   * `ca`
 * any other query parameters (for example, `application_name`) are preserved intact.
 
+### ClientConfig Compatibility for TypeScript
+
+The pg-connection-string `ConnectionOptions` interface is not compatible with the `ClientConfig` interface that [pg.Client](https://node-postgres.com/apis/client) expects. To remedy this, use the `parseIntoClientConfig` function instead of `parse`:
+
+```ts
+import { ClientConfig } from 'pg';
+import { parseIntoClientConfig } from 'pg-connection-string';
+
+const config: ClientConfig = parseIntoClientConfig('postgres://someuser:somepassword@somehost:381/somedatabase')
+```
+
+You can also use `toClientConfig` to convert an existing `ConnectionOptions` interface into a `ClientConfig` interface:
+
+```ts
+import { ClientConfig } from 'pg';
+import { parse, toClientConfig } from 'pg-connection-string';
+
+const config = parse('postgres://someuser:somepassword@somehost:381/somedatabase')
+const clientConfig: ClientConfig = toClientConfig(config)
+```
+
 ## Connection Strings
 
 The short summary of acceptable URLs is:

packages/pg-connection-string/index.d.ts

@@ -1,3 +1,5 @@
+import { ClientConfig } from 'pg'
+
 export function parse(connectionString: string): ConnectionOptions
 
 export interface ConnectionOptions {
@@ -13,3 +15,6 @@ export interface ConnectionOptions {
   fallback_application_name?: string
   options?: string
 }
+
+export function toClientConfig(config: ConnectionOptions): ClientConfig
+export function parseIntoClientConfig(connectionString: string): ClientConfig

packages/pg-connection-string/index.js

@@ -107,6 +107,62 @@ function parse(str) {
   return config
 }
 
+// convert pg-connection-string ssl config to a ClientConfig.ConnectionOptions
+function toConnectionOptions(sslConfig) {
+  const connectionOptions = Object.entries(sslConfig).reduce((c, [key, value]) => {
+    // we explicitly check for undefined and null instead of `if (value)` because some
+    // options accept falsy values. Example: `ssl.rejectUnauthorized = false`
+    if (value !== undefined && value !== null) {
+      c[key] = value
+    }
+
+    return c
+  }, {})
+
+  return connectionOptions
+}
+
+// convert pg-connection-string config to a ClientConfig
+function toClientConfig(config) {
+  const poolConfig = Object.entries(config).reduce((c, [key, value]) => {
+    if (key === 'ssl') {
+      const sslConfig = value
+
+      if (typeof sslConfig === 'boolean') {
+        c[key] = sslConfig
+      } else if (typeof sslConfig === 'object') {
+        c[key] = toConnectionOptions(sslConfig)
+      }
+    } else if (value !== undefined && value !== null) {
+      if (key === 'port') {
+        // when port is not specified, it is converted into an empty string
+        // we want to avoid NaN or empty string as a values in ClientConfig
+        if (value !== '') {
+          const v = parseInt(value, 10)
+          if (isNaN(v)) {
+            throw new Error(`Invalid ${key}: ${value}`)
+          }
+
+          c[key] = v
+        }
+      } else {
+        c[key] = value
+      }
+    }
+
+    return c
+  }, {})
+
+  return poolConfig
+}
+
+// parses a connection string into ClientConfig
+function parseIntoClientConfig(str) {
+  return toClientConfig(parse(str))
+}
+
 module.exports = parse
 
 parse.parse = parse
+parse.toClientConfig = toClientConfig
+parse.parseIntoClientConfig = parseIntoClientConfig

packages/pg-connection-string/test/toClientConfig.js

@@ -0,0 +1,94 @@
+'use strict'
+
+const chai = require('chai')
+const expect = chai.expect
+chai.should()
+
+const { parse, toClientConfig } = require('../')
+
+describe('toClientConfig', function () {
+  it('converts connection info', function () {
+    const config = parse('postgres://brian:pw@boom:381/lala')
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.user.should.equal('brian')
+    clientConfig.password.should.equal('pw')
+    clientConfig.host.should.equal('boom')
+    clientConfig.port.should.equal(381)
+    clientConfig.database.should.equal('lala')
+  })
+
+  it('converts query params', function () {
+    const config = parse(
+      'postgres:///?application_name=TheApp&fallback_application_name=TheAppFallback&client_encoding=utf8&options=-c geqo=off'
+    )
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.application_name.should.equal('TheApp')
+    clientConfig.fallback_application_name.should.equal('TheAppFallback')
+    clientConfig.client_encoding.should.equal('utf8')
+    clientConfig.options.should.equal('-c geqo=off')
+  })
+
+  it('converts SSL boolean', function () {
+    const config = parse('pg:///?ssl=true')
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.ssl.should.equal(true)
+  })
+
+  it('converts sslmode=disable', function () {
+    const config = parse('pg:///?sslmode=disable')
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.ssl.should.equal(false)
+  })
+
+  it('converts sslmode=noverify', function () {
+    const config = parse('pg:///?sslmode=no-verify')
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.ssl.rejectUnauthorized.should.equal(false)
+  })
+
+  it('converts other sslmode options', function () {
+    const config = parse('pg:///?sslmode=verify-ca')
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.ssl.should.deep.equal({})
+  })
+
+  it('converts other sslmode options', function () {
+    const config = parse('pg:///?sslmode=verify-ca')
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.ssl.should.deep.equal({})
+  })
+
+  it('converts ssl cert options', function () {
+    const connectionString =
+      'pg:///?sslcert=' +
+      __dirname +
+      '/example.cert&sslkey=' +
+      __dirname +
+      '/example.key&sslrootcert=' +
+      __dirname +
+      '/example.ca'
+    const config = parse(connectionString)
+    const clientConfig = toClientConfig(config)
+
+    clientConfig.ssl.should.deep.equal({
+      ca: 'example ca\n',
+      cert: 'example cert\n',
+      key: 'example key\n',
+    })
+  })
+
+  it('converts unix domain sockets', function () {
+    const config = parse('socket:/some path/?db=my[db]&encoding=utf8&client_encoding=bogus')
+    const clientConfig = toClientConfig(config)
+    clientConfig.host.should.equal('/some path/')
+    clientConfig.database.should.equal('my[db]', 'must to be escaped and unescaped through "my%5Bdb%5D"')
+    clientConfig.client_encoding.should.equal('utf8')
+  })
+})