Merge pull request #31 from gopherjs/goimports

playground: Add ability to fix imports via goimports.

Author: dmitshur

playground/index.html

@@ -12,6 +12,9 @@
 <spanid="controls">
 <inputtype="button" value="Run" ng-click="run(false)" />
 <inputtype="button" value="Format" ng-click="format()" />
+<labeltitle="Rewrite imports on Format">
+<inputng-model="imports" type="checkbox" />Imports
+</label>
 <inputtype="button" value="Share" ng-click="share()" />
 <inputtype="text" class="show-share-url-{{showShareUrl}}" id="share-url" value="{{shareUrl}}" onfocus="select()" />
 </span>

playground/internal/imports/fix.go

@@ -0,0 +1,179 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package imports
+
+import (
+"go/ast"
+"go/token"
+"path"
+"strings"
+
+"golang.org/x/tools/go/ast/astutil"
+)
+
+// importToGroup is a list of functions which map from an import path to
+// a group number.
+varimportToGroup= []func(importPathstring) (numint, okbool){
+func(importPathstring) (numint, okbool){
+ifstrings.HasPrefix(importPath, "appengine"){
+return2, true
+ }
+return
+ },
+func(importPathstring) (numint, okbool){
+ifstrings.Contains(importPath, "."){
+return1, true
+ }
+return
+ },
+}
+
+funcimportGroup(importPathstring) int{
+for_, fn:=rangeimportToGroup{
+ifn, ok:=fn(importPath); ok{
+returnn
+ }
+ }
+return0
+}
+
+funcfixImports(fset*token.FileSet, f*ast.File) (added []string, errerror){
+// refs are a set of possible package references currently unsatisfied by imports.
+// first key: either base package (e.g. "fmt") or renamed package
+// second key: referenced package symbol (e.g. "Println")
+refs:=make(map[string]map[string]bool)
+
+// decls are the current package imports. key is base package or renamed package.
+decls:=make(map[string]*ast.ImportSpec)
+
+// collect potential uses of packages.
+varvisitorvisitFn
+visitor=visitFn(func(node ast.Node) ast.Visitor{
+ifnode==nil{
+returnvisitor
+ }
+switchv:=node.(type){
+case*ast.ImportSpec:
+ifv.Name!=nil{
+decls[v.Name.Name] =v
+ } else{
+local:=importPathToName(strings.Trim(v.Path.Value, `\"`))
+decls[local] =v
+ }
+case*ast.SelectorExpr:
+xident, ok:=v.X.(*ast.Ident)
+if!ok{
+break
+ }
+ifxident.Obj!=nil{
+// if the parser can resolve it, it's not a package ref
+break
+ }
+pkgName:=xident.Name
+ifrefs[pkgName] ==nil{
+refs[pkgName] =make(map[string]bool)
+ }
+ifdecls[pkgName] ==nil{
+refs[pkgName][v.Sel.Name] =true
+ }
+ }
+returnvisitor
+ })
+ast.Walk(visitor, f)
+
+// Nil out any unused ImportSpecs, to be removed in following passes
+unusedImport:=map[string]bool{}
+forpkg, is:=rangedecls{
+ifrefs[pkg] ==nil&&pkg!="_"&&pkg!="."{
+unusedImport[strings.Trim(is.Path.Value, `"`)] =true
+ }
+ }
+foripath:=rangeunusedImport{
+ifipath=="C"{
+// Don't remove cgo stuff.
+continue
+ }
+astutil.DeleteImport(fset, f, ipath)
+ }
+
+// Search for imports matching potential package references.
+searches:=0
+typeresultstruct{
+ipathstring
+namestring
+errerror
+ }
+results:=make(chanresult)
+forpkgName, symbols:=rangerefs{
+iflen(symbols) ==0{
+continue// skip over packages already imported
+ }
+gofunc(pkgNamestring, symbolsmap[string]bool){
+ipath, rename, err:=findImport(pkgName, symbols)
+r:=result{ipath: ipath, err: err}
+ifrename{
+r.name=pkgName
+ }
+results<-r
+ }(pkgName, symbols)
+searches++
+ }
+fori:=0; i<searches; i++{
+result:=<-results
+ifresult.err!=nil{
+returnnil, result.err
+ }
+ifresult.ipath!=""{
+ifresult.name!=""{
+astutil.AddNamedImport(fset, f, result.name, result.ipath)
+ } else{
+astutil.AddImport(fset, f, result.ipath)
+ }
+added=append(added, result.ipath)
+ }
+ }
+
+returnadded, nil
+}
+
+// importPathToName returns the package name for the given import path.
+varimportPathToName=importPathToNameBasic
+
+// importPathToNameBasic assumes the package name is the base of import path.
+funcimportPathToNameBasic(importPathstring) (packageNamestring){
+returnpath.Base(importPath)
+}
+
+typepkgstruct{
+importpathstring// full pkg import path, e.g. "net/http"
+dirstring// absolute file path to pkg directory e.g. "/usr/lib/go/src/fmt"
+}
+
+// findImport searches for a package with the given symbols.
+// If no package is found, findImport returns "".
+// Declared as a variable rather than a function so goimports can be easily
+// extended by adding a file with an init function.
+varfindImport=findImportStdlib
+
+typevisitFnfunc(node ast.Node) ast.Visitor
+
+func (fnvisitFn) Visit(node ast.Node) ast.Visitor{
+returnfn(node)
+}
+
+funcfindImportStdlib(shortPkgstring, symbolsmap[string]bool) (importPathstring, renamebool, errerror){
+forsymbol:=rangesymbols{
+path:=stdlib[shortPkg+"."+symbol]
+ifpath==""{
+return"", false, nil
+ }
+ifimportPath!=""&&importPath!=path{
+// Ambiguous. Symbols pointed to different things.
+return"", false, nil
+ }
+importPath=path
+ }
+returnimportPath, false, nil
+}

playground/internal/imports/gen.go

@@ -0,0 +1,5 @@
+//go:generate go run mkapi.go -output=gopherjs.txt -gopath github.com/gopherjs/gopherjs/js
+//go:generate go run mkstdlib.go -output=zstdlib
+//go:generate rm gopherjs.txt
+
+package imports