node 0.4 compat, extend a running repl

lib/index.js

@@ -1,5 +1,5 @@
 //
-// Copyright 2010 Sami Samhuri @_sjs
+// Copyright 2010 - 2011 Sami Samhuri @_sjs
 // MIT license
 //
 // github.com/samsonjs/repl-edit
@@ -8,142 +8,150 @@
 // TODO proper error handling, better intregration with node/lib/repl.js
 
 var fs = require('fs')
-  , repl = require('repl')
-  , _repl
-  , _tmpdir
-
-// Find a suitable directory to store the REPL session
-if (process.env['TMPDIR']) _tmpdir = process.env['TMPDIR']
-else {
-    try {
-        fs.statSync('/tmp')
-        _tmpdir = '/tmp'
-    } catch (e) {
-        _tmpdir = process.cwd()
-    }
-}
-
-exports.startRepl = function() {
-    console.log('Commands: edit(), run(), stash(filename), unstash(filename), setEditor(editor)')
-    // TODO extend the repl context instead, problem is that repl.js:resetContext() isn't exported
-    //      so simple assignments to _repl.context can't survive .clear yet
-    exports.extend(global)
-    _repl = repl.start()
-    return exports
-}
-
-exports.extend = function(obj) {
-    var path = require('path')
   , spawn = require('child_process').spawn
-      , sys = require('sys')
+  , util = require('util')
-      , _tmpfile = path.join(_tmpdir, 'node-repl-' + process.pid + '.js')
 
-    obj.edit = function(editor) {
+module.exports = { startRepl: startRepl, extendRepl: extendRepl }
-        editor = editor || process.ENV['VISUAL'] || process.ENV['EDITOR']
+
-        // TODO seed the file with _repl.context._ if the file doesn't exist yet
+var repl
-        pausingRepl(function(unpause) {
+
+// Start a repl
+function startRepl() {
+  if (repl) {
+    console.error('repl is already running, only one instance is allowed')
+    return
+  }
+  extendRepl(require('repl').start())
+}
+
+function extendRepl(theRepl) {
+  if (repl) {
+    console.error('repl is already running, only one instance is allowed')
+    return
+  }
+
+  if (!theRepl || typeof theRepl.defineCommand !== function) {
+    console.error('bad argument, repl is not compatible')
+    return
+  }
+  
+  repl = theRepl
+
+  var tmpfile = makeTempfile()
+  process.on('exit', function() {
+    try {
+      fs.unlinkSync(tmpfile)
+    } catch (e) {
+      // might not exist
+    }
+  })
+
+  console.log('Commands: .edit, .run, .stash <filename>, .unstash <filename>, .editor <editor>')
+
+  repl.defineCommand('edit', {
+    help: 'Edit the current command in your text editor',
+    action: function(editor) {
+      edit(tmpfile, editor)
+    }
+  })
+
+  repl.defineCommand('run', {
+    help: 'Run the previously edited command',
+    action: function() {
+      pause()
+      run(tmpfile, function() { unpause() })
+    }
+  })
+
+  repl.defineCommand('stash', {
+    help: 'Write the current command to the named file',
+    action: function(dest) {
+      stash(tmpfile, dest)
+    }
+  })
+
+  repl.defineCommand('unstash', {
+    help: 'Replace the current command with the contents of the named file',
+    action: function(source) {
+      unstash(tmpfile, source)
+    }
+  })
+
+  repl.defineCommand('editor', function(editor) {
+    process.env['VISUAL'] = editor
+  })
+}
+
+// Commands
+
+function edit(cmdfile, editor) {
+  editor = editor || process.env['VISUAL'] || process.env['EDITOR']
+  // TODO seed the file with repl.context._ if the file doesn't exist yet
   var fds = [process.openStdin(), process.stdout, process.stdout]
-              , args = [_tmpfile]
+    , args = [cmdfile]
   // handle things like 'mate -w' and 'emacsclient --server-file <filename>'
   if (editor.match(/\s/)) {
     var words = editor.split(/\s+/) // FIXME this should do proper word splitting ...
     args = words.slice(1).concat(args)
     editor = words[0]
   }
+  pause()
   spawn(editor, args, {customFds: fds}).on('exit', function(code) {
     // some editors change the terminal resulting in skewed output, clean up
     spawn('reset').on('exit', function(_) {
       if (code === 0) {
-                        runFile(_tmpfile, function() { unpause() })
+        run(cmdfile, function() { unpause() })
       } else {
         unpause()
       }
     })
   })
-        })
+}
-    }
 
-    obj.run = function() {
+function stash(cmdFile, dest) {
-        pausingRepl(function(unpause) {
-            runFile(_tmpfile, function() { unpause() })
-        })
-    }
-
-    obj.setEditor = function(editor) {
-        process.ENV['VISUAL'] = editor
-    }
-
-    obj.stash = function(dest) {
   try {
-            fs.statSync(_tmpfile)
+    fs.statSync(cmdFile)
   } catch (e) {
     console.log('nothing to stash')
     return
   }
-        pausingRepl(function(unpause) {
+  var read = fs.createReadStream(cmdFile)
-            var read = fs.createReadStream(_tmpfile)
   read.on('end', function() {
     console.log('stashed')
     unpause()
   })
   // TODO confirm before overwriting an existing file
-            sys.pump(read, fs.createWriteStream(dest))
+  pause()
-        })
+  util.pump(read, fs.createWriteStream(dest))
-    }
+}
 
-    obj.unstash = function(source) {
+function unstash(cmdFile, source) {
   try {
     fs.statSync(source)
   } catch (e) {
     console.log('no stash at ' + source)
     return
   }
-        pausingRepl(function(unpause) {
   var read = fs.createReadStream(source)
   read.on('end', function() {
     console.log('unstashed')
     unpause()
   })
-            sys.pump(read, fs.createWriteStream(_tmpfile))
+  pause()
-        })
+  util.pump(read, fs.createWriteStream(cmdFile))
-    }
-
-    process.on('exit', function() {
-        try {
-            fs.unlinkSync(_tmpfile)
-        } catch (e) {
-            // might not exist
-        }
-    })
-    
-    return exports
 }
 
-function pausingRepl(fn) {
+function run(filename, callback) {
-    var origPrompt = _repl.prompt || '> '
-    _repl.stream.pause()
-    _repl.rli.enabled = false
-    _repl.prompt = ''
-    fn(function() {
-        _repl.prompt = origPrompt
-        _repl.rli.enabled = true
-        _repl.stream.resume()
-        _repl.displayPrompt()
-    })
-}
-
-function runFile(filename, callback) {
   // check if file exists. might not have been saved.
   try {
     fs.statSync(filename)
   } catch (e) {
-        _repl.stream.write('nothing to run\n')
+    repl.stream.write('nothing to run\n')
     callback()
     return
   }
 
-    var Script = process.binding('evals').Script
+  var evalcx = require('vm').Script.runInContext
-      , evalcx = Script.runInContext
     , read = fs.createReadStream(filename)
     , s = ''
   read.on('data', function(d) { s += d })
@@ -151,21 +159,58 @@ function runFile(filename, callback) {
     // The catchall for errors
     try {
       // Use evalcx to supply the global context
-            var ret = evalcx(s, _repl.context, "repl");
+      var ret = evalcx(s, repl.context, "repl");
       if (ret !== undefined) {
-                _repl.context._ = ret;
+        repl.context._ = ret;
         repl.writer(ret) + "\n"
       }
     } catch (e) {
       // On error: Print the error and clear the buffer
       if (e.stack) {
-                _repl.stream.write(e.stack + "\n");
+        repl.stream.write(e.stack + "\n");
       } else {
-                _repl.stream.write(e.toString() + "\n");
+        repl.stream.write(e.toString() + "\n");
       }
     }
     if (callback) callback()
   })
 }
 
-if (require.main === module) exports.startRepl()
+// Support
+
+var origPrompt
+function unpause() {
+  repl.prompt = origPrompt
+  repl.rli.enabled = true
+  repl.outputStream.resume()
+  repl.inputStream.resume()
+  repl.displayPrompt()
+}
+
+function pause() {
+  repl.outputStream.pause()
+  repl.inputStream.pause()
+  repl.rli.enabled = false
+  origPrompt = repl.prompt || '> '
+  repl.prompt = ''
+}
+
+function makeTempfile() {
+  var path = require('path')
+    , tmpdir
+
+  // Find a suitable directory to store the REPL session
+  if (process.env['TMPDIR']) tmpdir = process.env['TMPDIR']
+  else {
+    try {
+      fs.statSync('/tmp')
+      tmpdir = '/tmp'
+    } catch (e) {
+      tmpdir = process.cwd()
+    }
+  }
+  return path.join(tmpdir, 'node-repl-' + process.pid + '.js')
+}
+
+if (require.main === module) startRepl()
+else if (module.parent && module.parent.id === 'repl') extendRepl(module.parent.exports.repl)