feat: add config command (#1136)

compat.md

@@ -24,7 +24,7 @@
 | [client]               | :white_check_mark: |        :x:         |
 | [cluster]              | :white_check_mark: | :white_check_mark: |
 | [command]              | :white_check_mark: |        :x:         |
-| [config]               | :white_check_mark: |        :x:         |
+| [config]               | :white_check_mark: | :white_check_mark: |
 | [copy]                 | :white_check_mark: |        :x:         |
 | [dbsize]               | :white_check_mark: | :white_check_mark: |
 | [decr]                 | :white_check_mark: | :white_check_mark: |

src/commands/config.js

@@ -0,0 +1,51 @@
+export function config(_subcommand, ...args) {
+  if (!_subcommand) {
+    throw new Error("ERR wrong number of arguments for 'config' command")
+  }
+
+  const subcommand = _subcommand.toUpperCase()
+
+  if (subcommand === 'HELP' && args.length === 0) {
+    return [
+      'CONFIG <subcommand> [<arg> [value] [opt] ...]. Subcommands are:',
+      'GET <pattern>',
+      '    Return parameters matching the glob-like <pattern> and their values.',
+      'SET <directive> <value>',
+      '    Set the configuration <directive> to <value>.',
+      'RESETSTAT',
+      '    Reset statistics reported by the INFO command.',
+      'REWRITE',
+      '    Rewrite the configuration file.',
+      'HELP',
+      '    Prints this help.',
+    ]
+  }
+
+  if (subcommand === 'GET' && args.length > 0) {
+    return []
+  }
+
+  if (subcommand === 'SET' && args.length > 1) {
+    throw new Error(`ERR Unsupported CONFIG parameter: ${args[0]}`)
+  }
+
+  if (subcommand === 'RESETSTAT' && args.length === 0) {
+    return 'OK'
+  }
+
+  if (subcommand === 'REWRITE' && args.length === 0) {
+    throw new Error('ERR The server is running without a config file')
+  }
+
+  throw new Error(
+    `ERR Unknown subcommand or wrong number of arguments for '${_subcommand}'. Try CONFIG HELP.`
+  )
+}
+
+export function configBuffer(...args) {
+  const val = config.apply(this, args)
+  if (val?.map) {
+    return val.map(payload => (payload ? Buffer.from(payload) : payload))
+  }
+  return val ? Buffer.from(val) : val
+}

src/commands/index.js

@@ -5,6 +5,7 @@ export * from './bgrewriteaof'
 export * from './bgsave'
 export * from './brpoplpush'
 export * from './cluster'
+export * from './config'
 export * from './connect'
 export * from './dbsize'
 export * from './decr'

test/integration/commands/config.js

@@ -0,0 +1,160 @@
+import Redis from 'ioredis'
+
+// eslint-disable-next-line import/no-relative-parent-imports
+import { runTwinSuite } from '../../../test-utils'
+
+runTwinSuite('config', (command, equals) => {
+  describe(command, () => {
+    const redis = new Redis()
+
+    afterAll(() => {
+      redis.disconnect()
+    })
+
+    it('should throw on too few arguments', async () => {
+      expect.hasAssertions()
+
+      try {
+        await redis[command]()
+      } catch (err) {
+        expect(err.message).toMatch('wrong number of arguments')
+      }
+    })
+
+    it('should throw on unknown subcommand', async () => {
+      expect.hasAssertions()
+
+      try {
+        await redis[command]('foobar')
+      } catch (err) {
+        expect(err.message).toMatch('Unknown subcommand')
+      }
+    })
+
+    describe('get', () => {
+      it('should throw on wrong number of arguments', async () => {
+        expect.hasAssertions()
+
+        try {
+          await redis[command]('get')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+      })
+
+      it('returns a list over config options', async () => {
+        expect(await redis[command]('GET', '*')).toEqual(expect.any(Array))
+      })
+    })
+
+    describe('set', () => {
+      it('should throw on wrong number of arguments', async () => {
+        expect.assertions(2)
+
+        try {
+          await redis[command]('set')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+
+        try {
+          await redis[command]('SET', 'foo')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+      })
+
+      it('should throw as we actually do not support setting the config', async () => {
+        expect.hasAssertions()
+
+        try {
+          await redis[command]('SET', 'maxmockmemory', '1000000')
+        } catch (err) {
+          expect(err.message).toMatch(
+            'ERR Unsupported CONFIG parameter: maxmockmemory'
+          )
+        }
+      })
+    })
+
+    describe('resetstat', () => {
+      it('should throw on wrong number of arguments', async () => {
+        expect.hasAssertions()
+
+        try {
+          await redis[command]('RESETSTAT', 'foo')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+      })
+
+      it('returns OK', async () => {
+        expect(equals(await redis[command]('RESETSTAT'), 'OK')).toBe(true)
+      })
+    })
+
+    describe('rewrite', () => {
+      it('should throw on wrong number of arguments', async () => {
+        expect.hasAssertions()
+
+        try {
+          await redis[command]('REWRITE', 'foo')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+      })
+
+      it('throws as redis is running without a config file', async () => {
+        expect.hasAssertions()
+
+        try {
+          await redis[command]('REWRITE')
+        } catch (err) {
+          expect(err.message).toMatch(
+            'ERR The server is running without a config file'
+          )
+        }
+      })
+    })
+
+    describe('help', () => {
+      it('should throw on wrong number of arguments', async () => {
+        expect.assertions(2)
+
+        try {
+          await redis[command]('HELP', 'foo')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+
+        try {
+          await redis[command]('HELP', 'foo', 'bar')
+        } catch (err) {
+          expect(err.message).toMatch('wrong number of arguments')
+        }
+      })
+
+      it('prints a list over available subcommands', async () => {
+        const result = await redis[command]('HELP')
+
+        expect(
+          result.map(val => {
+            return Buffer.isBuffer(val) ? val.toString() : val
+          })
+        ).toEqual([
+          'CONFIG <subcommand> [<arg> [value] [opt] ...]. Subcommands are:',
+          'GET <pattern>',
+          '    Return parameters matching the glob-like <pattern> and their values.',
+          'SET <directive> <value>',
+          '    Set the configuration <directive> to <value>.',
+          'RESETSTAT',
+          '    Reset statistics reported by the INFO command.',
+          'REWRITE',
+          '    Rewrite the configuration file.',
+          'HELP',
+          '    Prints this help.',
+        ])
+      })
+    })
+  })
+})