ESM support

.eslintrc.json

@@ -2,13 +2,21 @@
   "root": true,
   "extends": ["./node_modules/sanctuary-style/eslint-es3.json"],
   "env": {"node": true},
+  "globals": {
+    "Promise": "readonly"
+  },
   "overrides": [
     {
       "files": ["lib/doctest.js"],
       "rules": {
         "no-multiple-empty-lines": ["error", {"max": 2, "maxEOF": 0}],
         "spaced-comment": ["error", "always", {"markers": ["/"]}]
       }
+    },
+    {
+      "files": ["*.mjs"],
+      "env": {"es6": true},
+      "parser": "babel-eslint"
     }
   ]
 }

.travis.yml

@@ -3,6 +3,7 @@ language: node_js
 node_js:
   - "6"
   - "8"
+  - "9"
   - "10"
 before_install:
   - git fetch origin refs/heads/master:refs/heads/master

README.md

@@ -46,16 +46,13 @@ $ doctest lib/temperature.js
 
 The exit code is 0 if all tests pass, 1 otherwise.
 
-### AMD and CommonJS modules
+### Supported module systems
 
-doctest supports CommonJS modules and partially supports AMD modules:
-
-| Module system               | Node.js |
-| --------------------------- |:-------:|
-| AMD                         |    ✔︎    |
-| AMD w/ dependencies         |    ✘    |
-| CommonJS                    |    ✔︎    |
-| CommonJS w/ dependencies    |    ✔︎    |
+| Module system         | Option        | Node.js       | Dependencies  |
+| --------------------- | ------------- |:-------------:|:-------------:|
+| AMD                   | `amd`         |       ✔︎       |       ✘       |
+| CommonJS              | `commonjs`    |       ✔︎       |       ✔︎       |
+| ECMAScript modules    | `esm`         |       ✔︎       |       ✔︎       |
 
 Specify module system via JavaScript API:
 

bin/doctest

@@ -2,18 +2,21 @@
 
 'use strict';
 
-// Based on:
-// https://github.com/jashkenas/coffeescript/blob/1.9.1/src/command.coffee#L431-L441
-var args = process.argv.slice (1);
+var path = require ('path');
+
+var esmSupported = Number ((process.versions.node.split ('.'))[0]) >= 9;
+var args = process.argv.slice (2);
 var idx = args.indexOf ('--nodejs');
-if (idx < 0 || idx === args.length - 1) {
-  require ('../lib/command');
-} else {
-  require ('child_process')
-  .spawn (process.execPath,
-          args[idx + 1]
-            .split (/\s+/)
-            .concat (args.slice (0, idx), args.slice (idx + 2)),
-          {cwd: process.cwd (), env: process.env, stdio: [0, 1, 2]})
-  .on ('exit', process.exit);
-}
+var flags = idx >= 0 && idx < args.length - 1;
+
+require ('child_process')
+.spawn (
+  process.execPath,
+  [].concat (esmSupported ? ['--experimental-modules'] : [])
+    .concat (flags ? args[idx + 1].split (/\s+/) : [])
+    .concat (['--', path.resolve (__dirname, '..', 'lib', 'command')])
+    .concat (flags ? (args.slice (0, idx)).concat (args.slice (idx + 2))
+                   : args),
+  {cwd: process.cwd (), env: process.env, stdio: [0, 1, 2]}
+)
+.on ('exit', process.exit);

lib/command.js

@@ -1,62 +1,19 @@
 'use strict';
 
-var program = require ('commander');
-
+var common = require ('./common');
+var program = require ('./program');
 var doctest = require ('..');
-var pkg = require ('../package.json');
-
-
-program
-.version (pkg.version)
-.usage ('[options] path/to/js/or/coffee/module')
-.option ('-m, --module <type>',
-         'specify module system ("amd" or "commonjs")')
-.option ('    --nodejs <options>',
-         'pass options directly to the "node" binary')
-.option ('    --prefix <prefix>',
-         'specify Transcribe-style prefix (e.g. ".")')
-.option ('    --opening-delimiter <delimiter>',
-         'specify line preceding doctest block (e.g. "```javascript")')
-.option ('    --closing-delimiter <delimiter>',
-         'specify line following doctest block (e.g. "```")')
-.option ('-p, --print',
-         'output the rewritten source without running tests')
-.option ('-s, --silent',
-         'suppress output')
-.option ('-t, --type <type>',
-         'specify file type ("coffee" or "js")')
-.parse (process.argv);
 
-//  formatErrors :: Array String -> String
-function formatErrors(errors) {
-  return (errors.map (function(s) { return 'error: ' + s + '\n'; })).join ('');
-}
 
-var errors = [];
-if (program.module != null &&
-    program.module !== 'amd' &&
-    program.module !== 'commonjs') {
-  errors.push ('Invalid module `' + program.module + "'");
-}
-if (program.type != null &&
-    program.type !== 'coffee' &&
-    program.type !== 'js') {
-  errors.push ('Invalid type `' + program.type + "'");
-}
-if (errors.length > 0) {
-  process.stderr.write (formatErrors (errors));
+if (program.module === 'esm') {
+  process.stderr.write (
+    common.formatErrors ([
+      'Node.js v' +
+      process.versions.node +
+      ' does not support ECMAScript modules (supported since v9.0.0)'
+    ])
+  );
   process.exit (1);
 }
 
-process.exit (program.args.reduce (function(status, path) {
-  var results;
-  try {
-    results = doctest (path, program);
-  } catch (err) {
-    process.stderr.write (formatErrors ([err.message]));
-    process.exit (1);
-  }
-  return results.reduce (function(status, tuple) {
-    return tuple[0] ? status : 1;
-  }, status);
-}, 0));
+common.runDoctests (doctest, program);

lib/command.mjs

@@ -0,0 +1,5 @@
+import common from './common';
+import program from './program';
+import doctest from '..';
+
+common.runDoctests (doctest, program);

lib/common.js

@@ -0,0 +1,38 @@
+'use strict';
+
+
+//  formatErrors :: Array String -> String
+exports.formatErrors = function(errors) {
+  return (errors.map (function(s) { return 'error: ' + s + '\n'; })).join ('');
+};
+
+//  sanitizeFileContents :: String -> String
+exports.sanitizeFileContents = function(contents) {
+  return contents.replace (/\r\n?/g, '\n').replace (/^#!.*/, '');
+};
+
+//  unlines :: Array String -> String
+exports.unlines = function(lines) {
+  return lines.reduce (function(s, line) { return s + line + '\n'; }, '');
+};
+
+exports.runDoctests = function(doctest, program) {
+  if (program.args.length === 0) {
+    process.stderr.write (exports.formatErrors ([
+      'No files for doctesting provided'
+    ]));
+    process.exit (1);
+  }
+  Promise.all (program.args.map (function(path) {
+    return (doctest (path, program)).then (function(results) {
+      return results.reduce (function(status, tuple) {
+        return tuple[0] ? status : 1;
+      }, 0);
+    });
+  })).then (function(statuses) {
+    process.exit (statuses.every (function(s) { return s === 0; }) ? 0 : 1);
+  }, function(err) {
+    process.stderr.write (exports.formatErrors ([err.message]));
+    process.exit (1);
+  });
+};

lib/doctest.js

@@ -18,12 +18,14 @@ var esprima = require ('esprima');
 var _show = require ('sanctuary-show');
 var Z = require ('sanctuary-type-classes');
 
+var common = require ('./common');
+
 
 function inferType(path) {
   switch (pathlib.extname (path)) {
     case '.coffee': return 'coffee';
     case '.js':     return 'js';
-    default:        throw new Error ('Cannot infer type from extension');
+    default:        return null;
   }
 }
 
@@ -39,36 +41,46 @@ module.exports = function(path, options) {
   if (options.module != null &&
       options.module !== 'amd' &&
       options.module !== 'commonjs') {
-    throw new Error ('Invalid module `' + options.module + "'");
+    return Promise.reject (new Error (
+      'Invalid module `' + options.module + "'"
+    ));
   }
   if (options.type != null &&
       options.type !== 'coffee' &&
       options.type !== 'js') {
-    throw new Error ('Invalid type `' + options.type + "'");
+    return Promise.reject (new Error (
+      'Invalid type `' + options.type + "'"
+    ));
+  }
+
+  var type = options.type == null ? inferType (path) : options.type;
+  if (type == null) {
+    return Promise.reject (new Error (
+      'Cannot infer type from extension'
+    ));
   }
 
   var source = toModule (
-    rewriters[options.type == null ? inferType (path) : options.type] (
+    rewriters[type] (
       {prefix: options.prefix == null ? '' : options.prefix,
        openingDelimiter: options.openingDelimiter,
-       closingDelimiter: options.closingDelimiter},
-      fs.readFileSync (path, 'utf8')
-        .replace (/\r\n?/g, '\n')
-        .replace (/^#!.*/, '')
+       closingDelimiter: options.closingDelimiter,
+       sourceType: 'script'},
+      common.sanitizeFileContents (fs.readFileSync (path, 'utf8'))
     ),
     options.module
   );
 
   if (options.print) {
     console.log (source.replace (/\n$/, ''));
-    return [];
+    return Promise.resolve ([]);
   } else if (options.silent) {
-    return evaluate (options.module, source, path);
+    return Promise.resolve (evaluate (options.module, source, path));
   } else {
     console.log ('running doctests in ' + path + '...');
     var results = evaluate (options.module, source, path);
     log (results);
-    return results;
+    return Promise.resolve (results);
   }
 };
 
@@ -111,11 +123,6 @@ function stripLeading(n, c, s) {
   return s.slice (idx);
 }
 
-//  unlines :: Array String -> String
-function unlines(lines) {
-  return lines.reduce (function(s, line) { return s + line + '\n'; }, '');
-}
-
 //  iifeWrap :: String -> String
 function iifeWrap(s) {
   return 'void function() {\n' + indentN (2, s) + '}.call(this);';
@@ -125,7 +132,7 @@ function iifeWrap(s) {
 function toModule(source, moduleType) {
   switch (moduleType) {
     case 'amd':
-      return unlines ([
+      return common.unlines ([
         source,
         'function define() {',
         '  for (var idx = 0; idx < arguments.length; idx += 1) {',
@@ -137,7 +144,7 @@ function toModule(source, moduleType) {
         '}'
       ]);
     case 'commonjs':
-      return iifeWrap (unlines ([
+      return iifeWrap (common.unlines ([
         'var __doctest = {',
         '  require: require,',
         '  queue: [],',
@@ -308,9 +315,12 @@ function substring(input, start, end) {
   );
 }
 
-function wrap$js(test) {
-  var type = (esprima.parse (test[INPUT].value)).body[0].type;
-  return type === 'FunctionDeclaration' || type === 'VariableDeclaration' ?
+function wrap$js(test, sourceType) {
+  var ast = esprima.parse (test[INPUT].value, {sourceType: sourceType});
+  var type = ast.body[0].type;
+  return type === 'FunctionDeclaration' ||
+         type === 'ImportDeclaration' ||
+         type === 'VariableDeclaration' ?
     test[INPUT].value :
     [
       '__doctest.enqueue({',
@@ -378,7 +388,16 @@ function rewrite$js(options, input) {
   //     produced by step 6 (substituting "step 6" for "step 2").
 
   function getComments(input) {
-    return (esprima.parse (input, {comment: true, loc: true})).comments;
+    var ast = esprima.parse (input, {
+      comment: true,
+      loc: true,
+      sourceType: options.sourceType
+    });
+    return ast.comments;
+  }
+
+  function wrapCode(js) {
+    return wrap$js (js, options.sourceType);
   }
 
   //  comments :: { Block :: Array Comment, Line :: Array Comment }
@@ -401,7 +420,7 @@ function rewrite$js(options, input) {
 
   //  source :: String
   var source = lineTests
-    .map (wrap$js)
+    .map (wrapCode)
     .concat ([''])
     .reduce (function(accum, s, idx) { return accum + chunks[idx] + s; }, '');
 
@@ -413,7 +432,7 @@ function rewrite$js(options, input) {
         substring (source, accum.loc, comment.loc.start),
         blockTests
           .filter (function(test) { return test.commentIndex === idx; })
-          .map (wrap$js)
+          .map (wrapCode)
           .join ('\n')
       );
       accum.loc = comment.loc.end;
@@ -423,6 +442,8 @@ function rewrite$js(options, input) {
     .join ('');
 }
 
+module.exports.rewrite$js = rewrite$js;
+
 function rewrite$coffee(options, input) {
   var lines = input.match (/^.*(?=\n)/gm);
   var chunks = lines.reduce (function(accum, line, idx) {
@@ -548,6 +569,8 @@ function run(queue) {
   }, {results: [], thunk: null}).results;
 }
 
+module.exports.run = run;
+
 function log(results) {
   console.log (results.reduce (function(s, tuple) {
     return s + (tuple[0] ? '.' : 'x');
@@ -559,3 +582,5 @@ function log(results) {
     }
   });
 }
+
+module.exports.log = log;