feat(cli): support stdin for input handling (fixes #71)

packages/cli/src/conversion.ts

@@ -0,0 +1,90 @@
+import type { DecodeOptions, Delimiter, EncodeOptions } from '../../toon/src'
+import type { InputSource } from './types'
+import * as fsp from 'node:fs/promises'
+import * as path from 'node:path'
+import process from 'node:process'
+import { consola } from 'consola'
+import { estimateTokenCount } from 'tokenx'
+import { decode, encode } from '../../toon/src'
+import { formatInputLabel, readInput } from './utils'
+
+export async function encodeToToon(config: {
+  input: InputSource
+  output?: string
+  delimiter: Delimiter
+  indent: number
+  lengthMarker: NonNullable<EncodeOptions['lengthMarker']>
+  printStats: boolean
+}): Promise<void> {
+  const jsonContent = await readInput(config.input)
+
+  let data: unknown
+  try {
+    data = JSON.parse(jsonContent)
+  }
+  catch (error) {
+    throw new Error(`Failed to parse JSON: ${error instanceof Error ? error.message : String(error)}`)
+  }
+
+  const encodeOptions: EncodeOptions = {
+    delimiter: config.delimiter,
+    indent: config.indent,
+    lengthMarker: config.lengthMarker,
+  }
+
+  const toonOutput = encode(data, encodeOptions)
+
+  if (config.output) {
+    await fsp.writeFile(config.output, toonOutput, 'utf-8')
+    const relativeInputPath = formatInputLabel(config.input)
+    const relativeOutputPath = path.relative(process.cwd(), config.output)
+    consola.success(`Encoded \`${relativeInputPath}\` → \`${relativeOutputPath}\``)
+  }
+  else {
+    console.log(toonOutput)
+  }
+
+  if (config.printStats) {
+    const jsonTokens = estimateTokenCount(jsonContent)
+    const toonTokens = estimateTokenCount(toonOutput)
+    const diff = jsonTokens - toonTokens
+    const percent = ((diff / jsonTokens) * 100).toFixed(1)
+
+    console.log()
+    consola.info(`Token estimates: ~${jsonTokens} (JSON) → ~${toonTokens} (TOON)`)
+    consola.success(`Saved ~${diff} tokens (-${percent}%)`)
+  }
+}
+
+export async function decodeToJson(config: {
+  input: InputSource
+  output?: string
+  indent: number
+  strict: boolean
+}): Promise<void> {
+  const toonContent = await readInput(config.input)
+
+  let data: unknown
+  try {
+    const decodeOptions: DecodeOptions = {
+      indent: config.indent,
+      strict: config.strict,
+    }
+    data = decode(toonContent, decodeOptions)
+  }
+  catch (error) {
+    throw new Error(`Failed to decode TOON: ${error instanceof Error ? error.message : String(error)}`)
+  }
+
+  const jsonOutput = JSON.stringify(data, undefined, config.indent)
+
+  if (config.output) {
+    await fsp.writeFile(config.output, jsonOutput, 'utf-8')
+    const relativeInputPath = formatInputLabel(config.input)
+    const relativeOutputPath = path.relative(process.cwd(), config.output)
+    consola.success(`Decoded \`${relativeInputPath}\` → \`${relativeOutputPath}\``)
+  }
+  else {
+    console.log(jsonOutput)
+  }
+}