fix: Better error on input type missmatch (fix eemeli#459)

src/errors.ts

@@ -25,6 +25,15 @@ export type ErrorCode =
 
 export type LinePos = { line: number; col: number }
 
+export class YAMLInputError extends Error {
+  constructor(message: string) {
+    super();
+    this.name = 'YAMLInputError'
+    this.message = message
+  }
+}
+
+
 export class YAMLError extends Error {
   name: 'YAMLParseError' | 'YAMLWarning'
   code: ErrorCode

src/public-api.ts

@@ -1,7 +1,7 @@
 import { Composer } from './compose/composer.js'
 import type { Reviver } from './doc/applyReviver.js'
 import { Document, Replacer } from './doc/Document.js'
-import { prettifyError, YAMLParseError } from './errors.js'
+import { prettifyError, YAMLParseError, YAMLInputError } from './errors.js'
 import { warn } from './log.js'
 import type { Node, ParsedNode } from './nodes/Node.js'
 import type {
@@ -50,6 +50,10 @@ export function parseAllDocuments<
         : Document<Contents, Strict>
     >
   | EmptyStream {
+  const inputType = typeof source;
+  if(inputType !== "string"){
+    throw new YAMLInputError(`Expected string, got ${inputType}`)
+  }
   const { lineCounter, prettyErrors } = parseOptions(options)
   const parser = new Parser(lineCounter?.addNewLine)
   const composer = new Composer(options)
@@ -82,6 +86,10 @@ export function parseDocument<
 ): Contents extends ParsedNode
   ? Document.Parsed<Contents, Strict>
   : Document<Contents, Strict> {
+  const inputType = typeof source;
+  if(inputType !== "string"){
+    throw new YAMLInputError(`Expected string, got ${inputType}`)
+  }
   const { lineCounter, prettyErrors } = parseOptions(options)
   const parser = new Parser(lineCounter?.addNewLine)
   const composer = new Composer(options)

tests/doc/parse.ts

@@ -2,6 +2,7 @@ import { readFileSync } from 'fs'
 import { resolve } from 'path'
 import * as YAML from 'yaml'
 import { source } from '../_utils'
+import {YAMLInputError} from "../../src/errors";
 
 describe('scalars', () => {
   test('empty block scalar at end of document', () => {
@@ -819,3 +820,20 @@ describe('CRLF line endings', () => {
     expect(res).toBe('foo bar')
   })
 })
+
+describe('Errors on non string inputs', () => {
+  test('rise in parseDocument', () => {
+    const scenario = () => {
+      const input = Buffer.alloc(8)
+      YAML.parseDocument(input)
+    }
+    expect(scenario).toThrow(YAMLInputError)
+  })
+  test.todo('rise in parseAllDocuments', () => {
+    const scenario = () => {
+      const input = Buffer.alloc(8)
+      YAML.parseAllDocuments(input)
+    }
+    expect(scenario).toThrow(YAMLInputError)
+  })
+})