From 827827ea208608708671e7fd9658a3331477afdf Mon Sep 17 00:00:00 2001
From: Misha Kaletsky <mmkal@users.noreply.github.com>
Date: Sun, 26 May 2024 14:51:45 -0400
Subject: [PATCH] recursion check + jsdoc

---
 src/index.ts         |  4 ++--
 src/logging.ts       | 29 +++++++++++++++++++++--------
 test/logging.test.ts | 22 ++++++++++++++++++++--
 3 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 9bde549..827e978 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -6,7 +6,7 @@ import {ZodError} from 'zod'
 import {type JsonSchema7Type} from 'zod-to-json-schema'
 import * as zodValidationError from 'zod-validation-error'
 import {flattenedProperties, incompatiblePropertyPairs, getDescription} from './json-schema'
-import {primitiveOrJsonConsoleLogger} from './logging'
+import {lineByLineConsoleLogger} from './logging'
 import {Logger, TrpcCliParams} from './types'
 import {parseProcedureInputs} from './zod-procedure'
 
@@ -52,7 +52,7 @@ export const trpcCli = <R extends AnyRouter>({router, ...params}: TrpcCliParams<
   )
 
   async function run(runParams?: {argv?: string[]; logger?: Logger; process?: {exit: (code: number) => never}}) {
-    const logger = {...primitiveOrJsonConsoleLogger, ...runParams?.logger}
+    const logger = {...lineByLineConsoleLogger, ...runParams?.logger}
     const _process = runParams?.process || process
     let verboseErrors: boolean = false
 
diff --git a/src/logging.ts b/src/logging.ts
index e86985c..af7e750 100644
--- a/src/logging.ts
+++ b/src/logging.ts
@@ -1,9 +1,13 @@
-import {LogMethod, Logger} from './types'
+import {LogMethod as LogFn, Logger} from './types'
 
-export const primitiveOrJsonLogger = getLoggerTransformer(log => {
-  const transformed: LogMethod = (...args) => {
-    if (args.length === 1 && Array.isArray(args[0])) {
-      args[0].forEach(item => transformed(item))
+export const lineByLineLogger = getLoggerTransformer(log => {
+  /**
+   * @param args values to log. if `logger.info('a', 1)` is called, `args` will be `['a', 1]`
+   * @param depth tracks whether the current call recursive. Used to make sure we don't flatten nested arrays
+   */
+  const wrapper = (args: unknown[], depth: number) => {
+    if (args.length === 1 && Array.isArray(args[0]) && depth === 0) {
+      args[0].forEach(item => wrapper([item], 1))
     } else if (args.every(isPrimitive)) {
       log(...args)
     } else if (args.length === 1) {
@@ -13,7 +17,7 @@ export const primitiveOrJsonLogger = getLoggerTransformer(log => {
     }
   }
 
-  return transformed
+  return (...args) => wrapper(args, 0)
 })
 
 const isPrimitive = (value: unknown): value is string | number | boolean => {
@@ -21,8 +25,9 @@ const isPrimitive = (value: unknown): value is string | number | boolean => {
   return type === 'string' || type === 'number' || type === 'boolean'
 }
 
-type TransformLogMethod = (method: LogMethod) => LogMethod
+type TransformLogMethod = (log: LogFn) => LogFn
 
+/** Takes a function that wraps an individual log function, and returns a function that wraps the `info` and `error` functions for a logger */
 function getLoggerTransformer(transform: TransformLogMethod) {
   return (logger: Logger): Logger => {
     const info = logger.info && transform(logger.info)
@@ -31,4 +36,12 @@ function getLoggerTransformer(transform: TransformLogMethod) {
   }
 }
 
-export const primitiveOrJsonConsoleLogger = primitiveOrJsonLogger(console)
+/**
+ * A logger which uses `console.log` and `console.error` to log in the following way:
+ * - Primitives are logged directly
+ * - Arrays are logged item-by-item
+ * - Objects are logged as JSON
+ *
+ * This is useful for logging structured data in a human-readable way, and for piping logs to other tools.
+ */
+export const lineByLineConsoleLogger = lineByLineLogger(console)
diff --git a/test/logging.test.ts b/test/logging.test.ts
index 1d88f09..99cf26d 100644
--- a/test/logging.test.ts
+++ b/test/logging.test.ts
@@ -1,10 +1,10 @@
 import {beforeEach, expect, test, vi} from 'vitest'
-import {primitiveOrJsonLogger} from '../src/logging'
+import {lineByLineLogger} from '../src/logging'
 
 const info = vi.fn()
 const error = vi.fn()
 const mocks = {info, error}
-const jsonish = primitiveOrJsonLogger(mocks)
+const jsonish = lineByLineLogger(mocks)
 
 beforeEach(() => {
   vi.clearAllMocks()
@@ -43,6 +43,24 @@ test('primitives array', async () => {
   `)
 })
 
+test('array array', async () => {
+  jsonish.info!([
+    ['m1', 'm2'],
+    ['m3', 'm4'],
+  ])
+
+  expect(info).toMatchInlineSnapshot(`
+    [
+      "m1",
+      "m2"
+    ]
+    [
+      "m3",
+      "m4"
+    ]
+  `)
+})
+
 test('multi primitives', async () => {
   jsonish.info!('m1', 11, true, 'm2')
   jsonish.info!('m1', 12, false, 'm2')