Support completion for node require(' // here Ctrl+Space shows fs, etc

Author: angelozerr

lib/tern.js

@@ -505,7 +505,7 @@
     return pos;
   }
 
-  function resolvePos(file, pos, tolerant) {
+  var resolvePos = exports.resolvePos = function(file, pos, tolerant) {
     if (typeof pos != "number") {
       var lineStart = findLineStart(file, pos.line);
       if (lineStart == null) {
@@ -539,7 +539,7 @@
     return {line: line, ch: pos - lineStart};
   }
 
-  function outputPos(query, file, pos) {
+  var outputPos = exports.outputPos = function(query, file, pos) {
     if (query.lineCharPositions) {
       var out = asLineChar(file, pos);
       if (file.type == "part")

plugin/node.js

@@ -168,9 +168,121 @@
 
     return {defs: defs,
             passes: {preCondenseReach: preCondenseReach,
-                     postLoadDef: postLoadDef}};
+                     postLoadDef: postLoadDef,
+                     completion: completion}};
   });
+  
+  /**
+   * Returns completion for require modules.
+   */
+  function completion(file, query) {   
+    var wordPos = tern.resolvePos(file, query.end);
+    var word = null, completions = [];
+    var cx = infer.cx(), server = cx.parent, data = server._node, locals = cx.definitions.node;
+    var currentFile = data.currentFile || resolveProjectPath(server, file.name);
+    var wrapAsObjs = query.types || query.depths || query.docs || query.urls || query.origins;
+    
+    function gather(modules) {
+      // loop for each modules
+      for(var name in modules) {
+        if (name != currentFile) {
+          // current module is different from the current file module
+          // resolve the module path
+          var moduleName = resolveModulePath(name, currentFile);
+          if (moduleName && !(query.filter !== false && word &&
+              (query.caseInsensitive ? moduleName.toLowerCase() : moduleName).indexOf(word) !== 0)) {
+            // module path matches the current word, add the module to the completion
+            var rec = wrapAsObjs ? {name: moduleName} : moduleName;
+            completions.push(rec);
+            
+            if ((query.types || query.docs || query.urls || query.origins)) {
+              var val = modules[name];
+              infer.resetGuessing();
+              var type = val.getType();
+              rec.guess = infer.didGuess();
+              if (query.types)
+                rec.type = "module";
+              if (query.docs)
+                maybeSet(rec, "doc", val.doc || type && type.doc);
+              if (query.urls)
+                maybeSet(rec, "url", val.url || type && type.url);
+              if (query.origins)
+                maybeSet(rec, "origin", val.origin || type && type.origin);
+            }            
+          }
+        }
+      }
+    }
+    
+    function getQuote(c) {
+      return c === '\'' || c === '"' ? c : null; 
+    }
+    
+    var callExpr = infer.findExpressionAround(file.ast, null, wordPos, file.scope, "CallExpression");
+    if (callExpr && callExpr.node.arguments && callExpr.node.callee && callExpr.node.callee.name === 'require') {      
+      var nodeArg = callExpr.node.arguments[0];
+      if (nodeArg) {
+        // here we are inside require(' node string
+        // compute the word to search and word start
+        var startQuote = getQuote(nodeArg.raw.charAt(0)), 
+            endQuote = getQuote(nodeArg.raw.length > 1 ? nodeArg.raw.charAt(nodeArg.raw.length - 1) : null);  
+        var wordEnd = endQuote != null ? nodeArg.end - 1: nodeArg.end,                         
+            wordStart = startQuote != null ? nodeArg.start + 1: nodeArg.start,    
+        word = nodeArg.value.slice(0, nodeArg.value.length - (wordEnd - wordPos));
+        if (query.caseInsensitive) word = word.toLowerCase();
+        // search from local node modules (fs, os, etc)
+        gather(locals);
+        // search from custom node modules
+        gather(data.modules);          
+        return {start: tern.outputPos(query, file, wordStart),
+           end: tern.outputPos(query, file, wordEnd),
+           isProperty: false,
+           isStringAround: true,
+           startQuote: startQuote,
+           endQuote: endQuote,
+           completions: completions};
+      }      
+    } 
+  }
+  
+  /**
+   * Resolve the module path of the given module name by using the current file. 
+   */
+  function resolveModulePath(name, currentFile) {
+    
+    function startsWith(str, prefix) {
+      return str.slice(0, prefix.length) == prefix;
+    }
 
+    function endsWith(str, suffix) {
+      return str.slice(-suffix.length) == suffix;
+    }
+    
+    if (name.indexOf('/') == -1) return name;
+    // module name has '/', compute the module path
+    var modulePath = normPath(relativePath(currentFile + '/..', name));
+    if (startsWith(modulePath, 'node_modules')) {
+      // module name starts with node_modules, remove it
+      modulePath = modulePath.substring('node_modules'.length + 1, modulePath.length);
+      if (endsWith(modulePath, 'index.js')) {
+        // module name ends with index.js, remove it.
+       modulePath = modulePath.substring(0, modulePath.length - 'index.js'.length - 1);
+      }
+    } else if (!startsWith(modulePath, '../')) {
+      // module name is not inside node_modules and there is not ../, add ./ 
+      modulePath = './' + modulePath;
+    }
+    if (endsWith(modulePath, '.js')) {
+      // remove js extension
+      modulePath = modulePath.substring(0, modulePath.length - '.js'.length);    
+    }    
+    return modulePath;
+  }
+  
+  function maybeSet(obj, prop, val) {
+    if (val != null) obj[prop] = val;
+  }
+   
   tern.defineQueryType("node_exports", {
     takesFile: true,
     run: function(server, query, file) {

test/cases/node/main.js

@@ -69,3 +69,8 @@ doc.f1; //doc: doc for f1
 doc.f2; //doc: doc for f2
 
 module.exports. //+
+
+// completion on known require module
+require("f //+ fs
+// completion on custom require module
+require("my //+ mymod