feat: merging functionality from minipass-json-stream

Author: wraithgar

lib/index.js

@@ -4,7 +4,7 @@ const { HttpErrorAuthOTP } = require('./errors.js')
 const checkResponse = require('./check-response.js')
 const getAuth = require('./auth.js')
 const fetch = require('make-fetch-happen')
-const JSONStream = require('minipass-json-stream')
+const JSONStream = require('./json-stream')
 const npa = require('npm-package-arg')
 const qs = require('querystring')
 const url = require('url')

lib/json-stream.js

@@ -0,0 +1,223 @@
+const Parser = require('jsonparse')
+const { Minipass } = require('minipass')
+
+class JSONStreamError extends Error {
+  constructor (err, caller) {
+    super(err.message)
+    Error.captureStackTrace(this, caller || this.constructor)
+  }
+
+  get name () {
+    return 'JSONStreamError'
+  }
+}
+
+const check = (x, y) =>
+  typeof x === 'string' ? String(y) === x
+  : x && typeof x.test === 'function' ? x.test(y)
+  : typeof x === 'boolean' || typeof x === 'object' ? x
+  : typeof x === 'function' ? x(y)
+  : false
+
+class JSONStream extends Minipass {
+  #count = 0
+  #ending = false
+  #footer = null
+  #header = null
+  #map = null
+  #onTokenOriginal
+  #parser
+  #path = null
+  #root = null
+
+  constructor (opts) {
+    super({
+      ...opts,
+      objectMode: true,
+    })
+
+    const parser = this.#parser = new Parser()
+    parser.onValue = value => this.#onValue(value)
+    this.#onTokenOriginal = parser.onToken
+    parser.onToken = (token, value) => this.#onToken(token, value)
+    parser.onError = er => this.#onError(er)
+
+    this.#path = typeof opts.path === 'string'
+      ? opts.path.split('.').map(e =>
+        e === '$*' ? { emitKey: true }
+        : e === '*' ? true
+        : e === '' ? { recurse: true }
+        : e)
+      : Array.isArray(opts.path) && opts.path.length ? opts.path
+      : null
+
+    if (typeof opts.map === 'function') {
+      this.#map = opts.map
+    }
+  }
+
+  #setHeaderFooter (key, value) {
+    // header has not been emitted yet
+    if (this.#header !== false) {
+      this.#header = this.#header || {}
+      this.#header[key] = value
+    }
+
+    // footer has not been emitted yet but header has
+    if (this.#footer !== false && this.#header === false) {
+      this.#footer = this.#footer || {}
+      this.#footer[key] = value
+    }
+  }
+
+  #onError (er) {
+    // error will always happen during a write() call.
+    const caller = this.#ending ? this.end : this.write
+    this.#ending = false
+    return this.emit('error', new JSONStreamError(er, caller))
+  }
+
+  #onToken (token, value) {
+    const parser = this.#parser
+    this.#onTokenOriginal.call(this.#parser, token, value)
+    if (parser.stack.length === 0) {
+      if (this.#root) {
+        const root = this.#root
+        if (!this.#path) {
+          super.write(root)
+        }
+        this.#root = null
+        this.#count = 0
+      }
+    }
+  }
+
+  #onValue (value) {
+    const parser = this.#parser
+    // the LAST onValue encountered is the root object.
+    // just overwrite it each time.
+    this.#root = value
+
+    if (!this.#path) {
+      return
+    }
+
+    let i = 0 // iterates on path
+    let j = 0 // iterates on stack
+    let emitKey = false
+    while (i < this.#path.length) {
+      const key = this.#path[i]
+      j++
+
+      if (key && !key.recurse) {
+        const c = (j === parser.stack.length) ? parser : parser.stack[j]
+        if (!c) {
+          return
+        }
+        if (!check(key, c.key)) {
+          this.#setHeaderFooter(c.key, value)
+          return
+        }
+        emitKey = !!key.emitKey
+        i++
+      } else {
+        i++
+        if (i >= this.#path.length) {
+          return
+        }
+        const nextKey = this.#path[i]
+        if (!nextKey) {
+          return
+        }
+        while (true) {
+          const c = (j === parser.stack.length) ? parser : parser.stack[j]
+          if (!c) {
+            return
+          }
+          if (check(nextKey, c.key)) {
+            i++
+            if (!Object.isFrozen(parser.stack[j])) {
+              parser.stack[j].value = null
+            }
+            break
+          } else {
+            this.#setHeaderFooter(c.key, value)
+          }
+          j++
+        }
+      }
+    }
+
+    // emit header
+    if (this.#header) {
+      const header = this.#header
+      this.#header = false
+      this.emit('header', header)
+    }
+    if (j !== parser.stack.length) {
+      return
+    }
+
+    this.#count++
+    const actualPath = parser.stack.slice(1)
+      .map(e => e.key).concat([parser.key])
+    if (value !== null && value !== undefined) {
+      const data = this.#map ? this.#map(value, actualPath) : value
+      if (data !== null && data !== undefined) {
+        const emit = emitKey ? { value: data } : data
+        if (emitKey) {
+          emit.key = parser.key
+        }
+        super.write(emit)
+      }
+    }
+
+    if (parser.value) {
+      delete parser.value[parser.key]
+    }
+
+    for (const k of parser.stack) {
+      k.value = null
+    }
+  }
+
+  write (chunk, encoding) {
+    if (typeof chunk === 'string') {
+      chunk = Buffer.from(chunk, encoding)
+    } else if (!Buffer.isBuffer(chunk)) {
+      return this.emit('error', new TypeError(
+        'Can only parse JSON from string or buffer input'))
+    }
+    this.#parser.write(chunk)
+    return this.flowing
+  }
+
+  end (chunk, encoding) {
+    this.#ending = true
+    if (chunk) {
+      this.write(chunk, encoding)
+    }
+
+    const h = this.#header
+    this.#header = null
+    const f = this.#footer
+    this.#footer = null
+    if (h) {
+      this.emit('header', h)
+    }
+    if (f) {
+      this.emit('footer', f)
+    }
+    return super.end()
+  }
+
+  static get JSONStreamError () {
+    return JSONStreamError
+  }
+
+  static parse (path, map) {
+    return new JSONStream({ path, map })
+  }
+}
+
+module.exports = JSONStream

test/index.js

@@ -1,8 +1,7 @@
-'use strict'
+const t = require('tap')
 
 const { Minipass } = require('minipass')
 const ssri = require('ssri')
-const t = require('tap')
 const zlib = require('zlib')
 const defaultOpts = require('../lib/default-opts.js')
 const tnock = require('./util/tnock.js')
@@ -273,50 +272,6 @@ t.test('query string with ?write=true', t => {
     .then(res => t.strictSame(res, { write: 'go for it' }))
 })
 
-t.test('fetch.json.stream()', async t => {
-  tnock(t, defaultOpts.registry).get('/hello').reply(200, {
-    a: 1,
-    b: 2,
-    c: 3,
-  })
-  const data = await fetch.json.stream('/hello', '$*', OPTS).collect()
-  t.same(data, [
-    { key: 'a', value: 1 },
-    { key: 'b', value: 2 },
-    { key: 'c', value: 3 },
-  ], 'got a streamed JSON body')
-})
-
-t.test('fetch.json.stream opts.mapJSON', async t => {
-  tnock(t, defaultOpts.registry).get('/hello').reply(200, {
-    a: 1,
-    b: 2,
-    c: 3,
-  })
-  const data = await fetch.json.stream('/hello', '*', {
-    ...OPTS,
-    mapJSON (value, [key]) {
-      return [key, value]
-    },
-  }).collect()
-  t.same(data, [
-    ['a', 1],
-    ['b', 2],
-    ['c', 3],
-  ], 'data mapped')
-})
-
-t.test('fetch.json.stream gets fetch error on stream', async t => {
-  await t.rejects(fetch.json.stream('/hello', '*', {
-    ...OPTS,
-    body: Promise.reject(new Error('no body for you')),
-    method: 'POST',
-    gzip: true, // make sure we don't gzip the promise, lol!
-  }).collect(), {
-    message: 'no body for you',
-  })
-})
-
 t.test('opts.ignoreBody', async t => {
   tnock(t, defaultOpts.registry)
     .get('/hello')

test/json-stream.js

@@ -0,0 +1,46 @@
+const t = require('tap')
+const { JSONStreamError, parse } = require('../lib/json-stream.js')
+
+t.test('JSONStream', (t) => {
+  t.test('JSONStreamError constructor', (t) => {
+    const error = new JSONStreamError(new Error('error'))
+    t.equal(error.message, 'error')
+    t.equal(error.name, 'JSONStreamError')
+    t.end()
+  })
+
+  t.test('JSONStream.write', (t) => {
+    t.test('JSONStream write error from numerical (not string not buffer)', async (t) => {
+      const stream = parse('*', {})
+      try {
+        stream.write(5)
+      } catch (error) {
+        t.equal(error.message, 'Can only parse JSON from string or buffer input')
+        t.equal(error.name, 'TypeError')
+      }
+      t.end()
+    })
+
+    t.end()
+  })
+
+  t.test('JSONStream.end', (t) => {
+    t.test(
+      'JSONStream end invalid chunk throws JSONStreamError from parser',
+      (t) => {
+        const stream = parse('*', {})
+        try {
+          stream.end('not a valid chunk')
+        } catch (error) {
+          t.equal(error.name, 'JSONStreamError')
+          t.equal(error.message, 'Unexpected "o" at position 1 in state STOP')
+        }
+        t.end()
+      }
+    )
+
+    t.end()
+  })
+
+  t.end()
+})