Error handling for undefined parquet file

package.json

@@ -27,15 +27,15 @@
     "typecheck": "tsc"
   },
   "devDependencies": {
-    "@types/node": "20.12.3",
+    "@types/node": "20.12.4",
     "@typescript-eslint/eslint-plugin": "7.5.0",
     "@vitest/coverage-v8": "1.4.0",
     "eslint": "8.57.0",
     "eslint-plugin-import": "2.29.1",
-    "eslint-plugin-jsdoc": "48.2.2",
+    "eslint-plugin-jsdoc": "48.2.3",
     "http-server": "14.1.1",
     "hysnappy": "0.3.0",
-    "typescript": "5.4.3",
+    "typescript": "5.4.4",
     "vitest": "1.4.0"
   }
 }

src/assemble.js

@@ -88,3 +88,5 @@ export function assembleObjects(
 
   return output
 }
+
+// TODO: depends on prior def level

src/metadata.js

@@ -29,6 +29,8 @@ import { deserializeTCompactProtocol } from './thrift.js'
  * @returns {Promise<FileMetaData>} parquet metadata object
  */
 export async function parquetMetadataAsync(asyncBuffer, initialFetchSize = 1 << 19 /* 512kb */) {
+  if (!asyncBuffer) throw new Error('parquet asyncBuffer is required')
+
   // fetch last bytes (footer) of the file
   const footerOffset = Math.max(0, asyncBuffer.byteLength - initialFetchSize)
   const footerBuffer = await asyncBuffer.slice(footerOffset)
@@ -64,12 +66,14 @@ export async function parquetMetadataAsync(asyncBuffer, initialFetchSize = 1 <<
 }
 
 /**
- * Read parquet metadata from a buffer
+ * Read parquet metadata from a buffer synchronously.
  *
  * @param {ArrayBuffer} arrayBuffer parquet file contents
  * @returns {FileMetaData} parquet metadata object
  */
 export function parquetMetadata(arrayBuffer) {
+  if (!arrayBuffer) throw new Error('parquet arrayBuffer is required')
+
   // DataView for easier manipulation of the buffer
   const view = new DataView(arrayBuffer)
 

src/read.js

@@ -30,6 +30,8 @@ import { getColumnName, isMapLike } from './schema.js'
  * @returns {Promise<void>} resolves when all requested rows and columns are parsed
  */
 export async function parquetRead(options) {
+  if (!options.file) throw new Error('parquet file is required')
+
   // load metadata if not provided
   options.metadata ||= await parquetMetadataAsync(options.file)
   if (!options.metadata) throw new Error('parquet metadata not found')

test/metadata.test.js

@@ -17,12 +17,17 @@ describe('parquetMetadata', () => {
     })
   })
 
-  it('should throw an error for a too short file', () => {
+  it('throws for arrayBuffer undefined', () => {
+    // @ts-expect-error testing invalid input
+    expect(() => parquetMetadata(undefined)).toThrow('parquet arrayBuffer is required')
+  })
+
+  it('throws for a too short file', () => {
     const arrayBuffer = new ArrayBuffer(0)
     expect(() => parquetMetadata(arrayBuffer)).toThrow('parquet file is too short')
   })
 
-  it('should throw an error for invalid metadata length', () => {
+  it('throws for invalid metadata length', () => {
     const arrayBuffer = new ArrayBuffer(12)
     const view = new DataView(arrayBuffer)
     view.setUint32(0, 0x31524150, true) // magic number PAR1
@@ -32,13 +37,13 @@ describe('parquetMetadata', () => {
       .toThrow('parquet metadata length 1000 exceeds available buffer 4')
   })
 
-  it('should throw an error for invalid magic number', () => {
+  it('throws for invalid magic number', () => {
     const arrayBuffer = new ArrayBuffer(8)
     expect(() => parquetMetadata(arrayBuffer))
       .toThrow('parquet file invalid (footer != PAR1)')
   })
 
-  it('should throw an error for invalid metadata length', () => {
+  it('throws for invalid metadata length', () => {
     const { buffer } = new Uint8Array([255, 255, 255, 255, 80, 65, 82, 49])
     expect(() => parquetMetadata(buffer))
       .toThrow('parquet metadata length 4294967295 exceeds available buffer 0')
@@ -56,15 +61,21 @@ describe('parquetMetadataAsync', () => {
     })
   })
 
-  it('should throw an error for invalid magic number', () => {
+  it('throws for asyncBuffer undefined', async () => {
+    const arrayBuffer = undefined
+    await expect(parquetMetadataAsync(arrayBuffer)).rejects
+      .toThrow('parquet asyncBuffer is required')
+  })
+
+  it('throws for invalid magic number', async () => {
     const { buffer } = new Uint8Array([255, 255, 255, 255, 255, 255, 255, 255])
-    expect(parquetMetadataAsync(buffer)).rejects
+    await expect(parquetMetadataAsync(buffer)).rejects
       .toThrow('parquet file invalid (footer != PAR1)')
   })
 
-  it('should throw an error for invalid metadata length', () => {
+  it('throws for invalid metadata length', async () => {
     const { buffer } = new Uint8Array([255, 255, 255, 255, 80, 65, 82, 49])
-    expect(parquetMetadataAsync(buffer)).rejects
+    await expect(parquetMetadataAsync(buffer)).rejects
       .toThrow('parquet metadata length 4294967295 exceeds available buffer 0')
   })
 })

test/read.test.js

@@ -34,6 +34,12 @@ describe('parquetRead', () => {
     })
   })
 
+  it('throws reasonable error messages', async () => {
+    const file = undefined
+    await expect(parquetRead({ file }))
+      .rejects.toThrow('parquet file is required')
+  })
+
   it('should read a single column from a file', async () => {
     const asyncBuffer = fileToAsyncBuffer('test/files/datapage_v2.snappy.parquet')
     await parquetRead({