1 files changed, 152 insertions, 0 deletions

diff --git a/lib/to-javascript.js b/lib/to-javascript.js
new file mode 100644
index 0000000..ce49704
--- /dev/null
+++ b/lib/to-javascript.js
@@ -0,0 +1,152 @@
+'use strict';
+
+var Promise = require('bluebird');
+
+var fs = Promise.promisifyAll(require('fs'));
+
+var path = require('path');
+
+var jsStringEscape = require('js-string-escape');
+
+var difference = require('lodash.difference');
+
+var debug_ = require('debug');
+
+var debug = debug_('purs-loader');
+
+var debugVerbose = debug_('purs-loader:verbose');
+
+var PsModuleMap = require('./purs-module-map');
+
+function updatePsModuleMap(psModule) {
+  var options = psModule.options;
+
+  var cache = psModule.cache;
+
+  var filePurs = psModule.srcPath;
+
+  if (!cache.psModuleMap) {
+    debugVerbose('module mapping does not exist - making a new module map');
+
+    cache.psModuleMap = PsModuleMap.makeMap(options.src);
+
+    return cache.psModuleMap;
+  } else {
+    debugVerbose('module mapping exists - updating module map for %s', filePurs);
+
+    cache.psModuleMap = cache.psModuleMap.then(function (psModuleMap) {
+      return PsModuleMap.makeMapEntry(filePurs).then(function (result) {
+        var map = Object.assign(psModuleMap, result);
+
+        return map;
+      });
+    });
+
+    return cache.psModuleMap;
+  }
+}
+
+// Reference the bundle.
+function makeBundleJS(psModule) {
+  var bundleOutput = psModule.options.bundleOutput;
+
+  var name = psModule.name;
+
+  var srcDir = psModule.srcDir;
+
+  var escaped = jsStringEscape(path.relative(srcDir, bundleOutput));
+
+  var result = 'module.exports = require("' + escaped + '")["' + name + '"]';
+
+  return Promise.resolve(result);
+}
+
+// Replace require paths to output files generated by psc with paths
+// to purescript sources, which are then also run through this loader.
+// Additionally, the imports replaced are tracked so that in the event
+// the compiler fails to compile the PureScript source, we can tack on
+// any new imports in order to allow webpack to watch the new files
+// before they have been successfully compiled.
+function makeJS(psModule, psModuleMap, js) {
+  var requireRE = /require\(['"]\.\.\/([\w\.]+)(?:\/index\.js)?['"]\)/g;
+
+  var foreignRE = /require\(['"]\.\/foreign(?:\.js)?['"]\)/g;
+
+  var name = psModule.name;
+
+  var imports = psModuleMap[name].imports;
+
+  var replacedImports = [];
+
+  var result = js.replace(requireRE, function (m, p1) {
+    var moduleValue = psModuleMap[p1];
+
+    if (!moduleValue) {
+      debug('module %s was not found in the map, replacing require with null', p1);
+
+      return 'null';
+    } else {
+      var escapedPath = jsStringEscape(moduleValue.src);
+
+      replacedImports.push(p1);
+
+      return 'require("' + escapedPath + '")';
+    }
+  }).replace(foreignRE, function () {
+    var escapedPath = jsStringEscape(psModuleMap[name].ffi);
+
+    return 'require("' + escapedPath + '")';
+  });
+
+  var additionalImports = difference(imports, replacedImports);
+
+  if (!additionalImports.length) {
+    return Promise.resolve(result);
+  } else {
+    debug('rebuilding module map due to additional imports for %s: %o', name, additionalImports);
+
+    psModule.cache.psModuleMap = null;
+
+    return updatePsModuleMap(psModule).then(function (updatedPsModuleMap) {
+      var additionalImportsResult = additionalImports.map(function (import_) {
+        var moduleValue = updatedPsModuleMap[import_];
+
+        if (!moduleValue) {
+          debug('module %s was not found in the map, skipping require', import_);
+
+          return null;
+        } else {
+          var escapedPath = jsStringEscape(moduleValue.src);
+
+          return 'var ' + import_.replace(/\./g, '_') + ' = require("' + escapedPath + '")';
+        }
+      }).filter(function (a) {
+        return a !== null;
+      }).join('\n');
+
+      return result + '\n' + additionalImportsResult;
+    });
+  }
+}
+
+module.exports = function toJavaScript(psModule) {
+  var options = psModule.options;
+
+  var cache = psModule.cache;
+
+  var bundlePath = path.resolve(options.bundleOutput);
+
+  var jsPath = options.bundle ? bundlePath : psModule.jsPath;
+
+  var js = fs.readFileAsync(jsPath, 'utf8').catch(function () {
+    return '';
+  });
+
+  var psModuleMap = updatePsModuleMap(psModule);
+
+  debugVerbose('loading JavaScript for %s', psModule.name);
+
+  return Promise.props({ js: js, psModuleMap: psModuleMap }).then(function (result) {
+    return options.bundle ? makeBundleJS(psModule) : makeJS(psModule, result.psModuleMap, result.js);
+  });
+};
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