module: support multi-dot file extension

Support multi-dot file extensions like '.coffee.md' in Module.load. PR-URL: #23416 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: John-David Dalton <[email protected]>

Author: GeoffreyBooth

lib/internal/modules/cjs/loader.js

@@ -217,6 +217,22 @@ function tryExtensions(p, exts, isMain){
 returnfalse;
 }
 
+// find the longest (possibly multi-dot) extension registered in
+// Module._extensions
+functionfindLongestRegisteredExtension(filename){
+constname=path.basename(filename);
+letcurrentExtension;
+letindex;
+letstartIndex=0;
+while((index=name.indexOf('.',startIndex))!==-1){
+startIndex=index+1;
+if(index===0)continue;// Skip dotfiles like .gitignore
+currentExtension=name.slice(index);
+if(Module._extensions[currentExtension])returncurrentExtension;
+}
+return'.js';
+}
+
 varwarned=false;
 Module._findPath=function(request,paths,isMain){
 if(path.isAbsolute(request)){
@@ -595,8 +611,7 @@ Module.prototype.load = function(filename){
 this.filename=filename;
 this.paths=Module._nodeModulePaths(path.dirname(filename));
 
-varextension=path.extname(filename)||'.js';
-if(!Module._extensions[extension])extension='.js';
+varextension=findLongestRegisteredExtension(filename);
 Module._extensions[extension](this,filename);
 this.loaded=true;
 

test/known_issues/test-module-deleted-extensions.js

@@ -0,0 +1,94 @@
+'use strict';
+
+// Refs: https://github.com/nodejs/node/issues/4778
+
+constcommon=require('../common');
+constassert=require('assert');
+constfs=require('fs');
+constpath=require('path');
+constModule=require('module');
+consttmpdir=require('../common/tmpdir');
+constfile=path.join(tmpdir.path,'test-extensions.foo.bar');
+constdotfile=path.join(tmpdir.path,'.bar');
+constdotfileWithExtension=path.join(tmpdir.path,'.foo.bar');
+
+tmpdir.refresh();
+fs.writeFileSync(file,'console.log(__filename);','utf8');
+fs.writeFileSync(dotfile,'console.log(__filename);','utf8');
+fs.writeFileSync(dotfileWithExtension,'console.log(__filename);','utf8');
+
+{
+require.extensions['.bar']=common.mustNotCall();
+require.extensions['.foo.bar']=common.mustCall();
+constmodulePath=path.join(tmpdir.path,'test-extensions');
+require(modulePath);
+require(file);
+deleterequire.cache[file];
+deleterequire.extensions['.bar'];
+deleterequire.extensions['.foo.bar'];
+Module._pathCache=Object.create(null);
+}
+
+{
+require.extensions['.foo.bar']=common.mustCall();
+constmodulePath=path.join(tmpdir.path,'test-extensions');
+require(modulePath);
+assert.throws(
+()=>require(`${modulePath}.foo`),
+newError(`Cannot find module '${modulePath}.foo'`)
+);
+require(`${modulePath}.foo.bar`);
+deleterequire.cache[file];
+deleterequire.extensions['.foo.bar'];
+Module._pathCache=Object.create(null);
+}
+
+{
+constmodulePath=path.join(tmpdir.path,'test-extensions');
+assert.throws(
+()=>require(modulePath),
+newError(`Cannot find module '${modulePath}'`)
+);
+deleterequire.cache[file];
+Module._pathCache=Object.create(null);
+}
+
+{
+require.extensions['.bar']=common.mustNotCall();
+require.extensions['.foo.bar']=common.mustCall();
+constmodulePath=path.join(tmpdir.path,'test-extensions.foo');
+require(modulePath);
+deleterequire.cache[file];
+deleterequire.extensions['.bar'];
+deleterequire.extensions['.foo.bar'];
+Module._pathCache=Object.create(null);
+}
+
+{
+require.extensions['.foo.bar']=common.mustNotCall();
+constmodulePath=path.join(tmpdir.path,'test-extensions.foo');
+assert.throws(
+()=>require(modulePath),
+newError(`Cannot find module '${modulePath}'`)
+);
+deleterequire.extensions['.foo.bar'];
+Module._pathCache=Object.create(null);
+}
+
+{
+require.extensions['.bar']=common.mustNotCall();
+require(dotfile);
+deleterequire.cache[dotfile];
+deleterequire.extensions['.bar'];
+Module._pathCache=Object.create(null);
+}
+
+{
+require.extensions['.bar']=common.mustCall();
+require.extensions['.foo.bar']=common.mustNotCall();
+require(dotfileWithExtension);
+deleterequire.cache[dotfileWithExtension];
+deleterequire.extensions['.bar'];
+deleterequire.extensions['.foo.bar'];
+Module._pathCache=Object.create(null);
+}