Add proper tests, exception handling, implement getAbstractName

src/runtime/javascript/errno.ts

@@ -0,0 +1,49 @@
+interface ErrorInfo {
+  errno: number
+  code: string
+  description: string
+}
+
+// taken from /usr/include/asm-generic/errno-base.h
+const errs: ErrorInfo[] = [
+  { code: 'EPERM', errno: 1, description: 'Operation not permitted' },
+  { code: 'ENOENT', errno: 2, description: 'No such file or directory' },
+  { code: 'ESRCH', errno: 3, description: 'No such process' },
+  { code: 'EINTR', errno: 4, description: 'Interrupted system call' },
+  { code: 'EIO', errno: 5, description: 'I/O error' },
+  { code: 'ENXIO', errno: 6, description: 'No such device or address' },
+  { code: 'E2BIG', errno: 7, description: 'Argument list too long' },
+  { code: 'ENOEXEC', errno: 8, description: 'Exec format error' },
+  { code: 'EBADF', errno: 9, description: 'Bad file number' },
+  { code: 'ECHILD', errno: 10, description: 'No child processes' },
+  { code: 'EAGAIN', errno: 11, description: 'Try again' },
+  { code: 'ENOMEM', errno: 12, description: 'Out of memory' },
+  { code: 'EACCES', errno: 13, description: 'Permission denied' },
+  { code: 'EFAULT', errno: 14, description: 'Bad address' },
+  { code: 'ENOTBLK', errno: 15, description: 'Block device required' },
+  { code: 'EBUSY', errno: 16, description: 'Device or resource busy' },
+  { code: 'EEXIST', errno: 17, description: 'File exists' },
+  { code: 'EXDEV', errno: 18, description: 'Cross-device link' },
+  { code: 'ENODEV', errno: 19, description: 'No such device' },
+  { code: 'ENOTDIR', errno: 20, description: 'Not a directory' },
+  { code: 'EISDIR', errno: 21, description: 'Is a directory' },
+  { code: 'EINVAL', errno: 22, description: 'Invalid argument' },
+  { code: 'ENFILE', errno: 23, description: 'File table overflow' },
+  { code: 'EMFILE', errno: 24, description: 'Too many open files' },
+  { code: 'ENOTTY', errno: 25, description: 'Not a typewriter' },
+  { code: 'ETXTBSY', errno: 26, description: 'Text file busy' },
+  { code: 'EFBIG', errno: 27, description: 'File too large' },
+  { code: 'ENOSPC', errno: 28, description: 'No space left on device' },
+  { code: 'ESPIPE', errno: 29, description: 'Illegal seek' },
+  { code: 'EROFS', errno: 30, description: 'Read-only file system' },
+  { code: 'EMLINK', errno: 31, description: 'Too many links' },
+  { code: 'EPIPE', errno: 32, description: 'Broken pipe' },
+  { code: 'EDOM', errno: 33, description: 'Math argument out of domain of func' },
+  { code: 'ERANGE', errno: 34, description: 'Math result not representable' }
+]
+
+export default {
+  lookup(errno: number): string | undefined {
+    return errs.find(err => err.errno === errno)?.description
+  }
+}

src/runtime/javascript/index.ts

@@ -1,44 +1,122 @@
+import errno from './errno'
+import ffi from 'ffi'
 import { deref } from 'ref'
-import * as ref from 'ref'
-import * as ffi from 'ffi'
+import ref from 'ref'
+import Struct from 'ref-struct'
+
+// ----------------------------------------------------------------------------
+// FFI "Types"
 
 const PgfDB = ref.types.int
 const PgfDBPtr = ref.refType(PgfDB)
 const PgfRevision = ref.types.int
 const PgfRevisionPtr = ref.refType(PgfRevision)
-const PgfExn = ref.types.int
-const PgfExnPtr = ref.refType(PgfExn)
-// const stringPtr = ref.refType(ref.types.CString)
-
-const PGF = ffi.Library('libpgf', {
-  'pgf_read_pgf': [ PgfDBPtr, [ 'string', PgfRevisionPtr, PgfExnPtr ] ],
-  'pgf_write_pgf': [ 'void', [ 'string', PgfDBPtr, PgfRevisionPtr, PgfExnPtr ] ],
+const PgfExn = Struct({
+  type: ref.types.int,
+  code: ref.types.int,
+  msg: ref.types.CString
 })
+const PgfExnPtr = ref.refType(PgfExn)
+const PgfText = Struct({
+  size: ref.types.size_t,
+  text: ref.types.char // char[]
+})
+const PgfTextPtr = ref.refType(PgfText)
+
+// ----------------------------------------------------------------------------
+// TypeScript Types
 
 interface Pointer extends Buffer {
   deref(): any
 }
 
-interface State {
-  db: Pointer,
-  revision: number
-}
-const state: State = {
-  db: ref.NULL_POINTER as Pointer,
-  revision: 0
-}
-
-export default {
-  readPGF: function (path: string) {
-    const rev = ref.alloc(PgfRevision) as Pointer
-    const err = ref.alloc(PgfExn) as Pointer
-    const db = PGF.pgf_read_pgf(path, rev, err)
-    if (err.deref() === 0) {
-      state.db = db
-      state.revision = rev.deref()
-      console.log(`ok`)
-    } else {
-      console.error(`error ${err.deref()}`)
-    }
+class PGFError extends Error {
+  constructor(message: string) {
+    super(message)
   }
 }
+
+// ----------------------------------------------------------------------------
+// FFI
+
+const runtime = ffi.Library('libpgf', {
+  'pgf_read_pgf': [ PgfDBPtr, [ ref.types.CString, PgfRevisionPtr, PgfExnPtr ] ],
+  'pgf_write_pgf': [ ref.types.void, [ ref.types.CString, PgfDBPtr, PgfRevisionPtr, PgfExnPtr ] ],
+  'pgf_abstract_name': [ PgfTextPtr, [ PgfDBPtr, PgfRevision, PgfExnPtr ] ],
+})
+
+// ----------------------------------------------------------------------------
+// Helpers
+
+function handleError (errPtr: Pointer): void {
+  const err = errPtr.deref()
+  switch (err.type) {
+    // PGF_EXN_NONE
+    case 0: return
+
+    // PGF_EXN_SYSTEM_ERROR
+    case 1:
+      const desc = errno.lookup(err.code)
+      throw new Error(`${desc}: ${err.msg}`)
+
+    // PGF_EXN_PGF_ERROR
+    case 2:
+      throw new PGFError(err.msg)
+
+    // PGF_EXN_OTHER_ERROR
+    case 3:
+      throw new Error(err.msg)
+
+    default:
+      throw new Error(`unknown error type: ${err.type}`)
+  }
+}
+
+function PgfText_AsString (txtPtr: Pointer) {
+  const txtSize = txtPtr.deref().size
+  const charPtr = ref.reinterpret(txtPtr, txtSize, ref.types.size_t.size)
+  return charPtr.toString('utf8')
+}
+
+// ----------------------------------------------------------------------------
+// PGF grammar object
+
+class PGF {
+  db: Pointer
+  revision: number
+
+  constructor () {
+    this.db = ref.NULL_POINTER as Pointer
+    this.revision = 0
+  }
+
+  getAbstractName () {
+    const err = ref.alloc(PgfExn) as Pointer
+    const txt = runtime.pgf_abstract_name(this.db, this.revision, err)
+    handleError(err)
+    return PgfText_AsString(txt)
+  }
+
+}
+
+// ----------------------------------------------------------------------------
+// PGF module functions
+
+function readPGF (path: string): PGF {
+  const rev = ref.alloc(PgfRevision) as Pointer
+  const err = ref.alloc(PgfExn) as Pointer
+  const db = runtime.pgf_read_pgf(path, rev, err)
+  handleError(err)
+
+  const state = new PGF()
+  state.db = db
+  state.revision = rev.deref()
+  return state
+}
+
+// ----------------------------------------------------------------------------
+// Exposed library API
+
+export default {
+  readPGF
+}

src/runtime/javascript/jest.config.js

@@ -0,0 +1,5 @@
+/** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node'
+};

src/runtime/javascript/package.json

@@ -5,7 +5,7 @@
   "main": "dist/index.js",
   "scripts": {
     "build": "npx tsc",
-    "test": "ts-node ./tests/basic.ts"
+    "test": "npx jest"
   },
   "author": "John J. Camilleri",
   "license": "ISC",
@@ -14,7 +14,9 @@
   },
   "devDependencies": {
     "@types/ffi": "^0.2.3",
-    "ts-node": "^10.2.1",
+    "@types/jest": "^27.0.2",
+    "jest": "^27.2.4",
+    "ts-jest": "^27.0.5",
     "typescript": "^4.4.3"
   }
 }

src/runtime/javascript/tests/basic.test.ts

@@ -0,0 +1,16 @@
+import PGF from '../index'
+
+test('readPGF successful', () => {
+  let gr = PGF.readPGF('../haskell/tests/basic.pgf')
+})
+
+test('readPGF missing file', () => {
+  expect(() => {
+    PGF.readPGF('abc.pgf')
+  }).toThrow()
+})
+
+test('abstract name', () => {
+  let gr = PGF.readPGF('../haskell/tests/basic.pgf')
+  expect(gr.getAbstractName()).toBe('basic')
+})

src/runtime/javascript/tests/basic.ts

@@ -1,3 +0,0 @@
-import PGF from '../index'
-
-PGF.readPGF('../haskell/tests/basic.pgf')