Update README.md and HACKING.md and resulting yak shave.

sky/tools/skygo/sky_server.go

 // Copyright (c) 2014 The Chromium 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 main
 
 import (
         "flag"
         "fmt"
         "io/ioutil"
         "net/http"
         "os"
         "path"
         "path/filepath"
         "strings"
 )
 
+var verbose bool = false;
+
 type skyHandlerRoot struct {
         root string
 }
 
 func skyHandler(root string) http.Handler {
         return &skyHandlerRoot{root}
 }
 
 func (handler *skyHandlerRoot) ServeHTTP(w http.ResponseWriter, r *http.Request) {
         if strings.HasPrefix(r.URL.Path, "/.git") {
                 w.WriteHeader(http.StatusNotFound)
                 return
         }
         path := path.Join(handler.root, r.URL.Path)
+
+        // Remove this one once .sky files are gone:
         if strings.HasSuffix(path, ".sky") {
                 w.Header().Set("Content-Type", "text/sky")
         }
+
+        if strings.HasSuffix(path, ".dart") {
+                w.Header().Set("Content-Type", "application/dart")
+        }
         w.Header().Set("Cache-Control", "no-cache")
         http.ServeFile(w, r, path)
 }
 
 func usage() {
-        fmt.Fprintf(os.Stderr, "Usage: sky_server [flags] MOJO_SRC_ROOT PORT\n\n")
-        fmt.Fprintf(os.Stderr, "launches a basic http server with mappings into the\n")
-        fmt.Fprintf(os.Stderr, "mojo repository for framework/service paths.\n")
-        fmt.Fprintf(os.Stderr, "[flags] MUST be before arguments, because go:flag.\n\n")
+        fmt.Fprintf(os.Stderr, "Usage: sky_server [flags] MOJO_SRC_ROOT PACKAGE_ROOT\n")
+        fmt.Fprintf(os.Stderr, "Launches a basic http server with mappings into the mojo repository for framework/service paths.\n")
+        fmt.Fprintf(os.Stderr, "MOJO_SRC_ROOT must be the root of the Mojo repository.\n")
+        fmt.Fprintf(os.Stderr, "PACKAGE_ROOT must be the root of your Dart packages (e.g. out/Debug/gen/dart-pkg/packages/).\n")
         flag.PrintDefaults()
         os.Exit(2)
 }
 
 func addMapping(from_path string, to_path string) {
-        // Print to stderr to it's more obvious what this binary does.
-        fmt.Fprintf(os.Stderr, "  %s -> %s\n", from_path, to_path)
+        if (verbose) {
+                fmt.Fprintf(os.Stderr, "  %s -> %s\n", from_path, to_path)
+        }
         http.Handle(from_path, http.StripPrefix(from_path, skyHandler(to_path)))
 }
 
-func main() {
-        var configuration = flag.String("t", "Release", "The target configuration (i.e. Release or Debug)")
+func setupMappings(mojoRoot string, packageRoot string, port int) {
+        if (verbose) {
+                fmt.Fprintf(os.Stderr, "Mappings for localhost:%v:\n", port)
+                fmt.Fprintf(os.Stderr, "  / -> %s\n", mojoRoot)
+        }
+        http.Handle("/", skyHandler(mojoRoot))
 
-        flag.Parse()
-        flag.Usage = usage
-        // The built-in go:flag is awful.  It only allows short-name arguments
-        // and they *must* be before any unnamed arguments.  There are better ones:
-        // https://godoc.org/github.com/jessevdk/go-flags
-        // but for now we're using raw-go.
-        if flag.NArg() != 3 {
-                usage()
+        if (verbose) {
+                fmt.Fprintf(os.Stderr, "  /echo_post -> custom echo handler\n")
         }
-
-        root, _ := filepath.Abs(flag.Arg(0))
-        port := flag.Arg(1)
-        packageRoot := flag.Arg(2)
-
-        // genRoot should not be needed once we figure out how mojom generation
-        // for sdk users should work.
-        genRoot := path.Join(root, "out", *configuration, "gen")
-
-        fmt.Fprintf(os.Stderr, "Mappings for localhost:%s:\n", port)
-
-        fmt.Fprintf(os.Stderr, "  / -> %s\n", root)
-        http.Handle("/", skyHandler(root))
-
-        fmt.Fprintf(os.Stderr, "  /echo_post -> custom echo handler\n")
         http.HandleFunc("/echo_post", func(w http.ResponseWriter, r *http.Request) {
                 defer r.Body.Close()
                 body, _ := ioutil.ReadAll(r.Body)
                 w.Write(body)
         })
 
-        addMapping("/gen/", genRoot)
         addMapping("/packages/", packageRoot)
+}
 
-        http.ListenAndServe(":"+port, nil)
+func main() {
+        var portPtr = flag.Int("p", 8000, "The HTTP port")
+        var verbosePtr = flag.Bool("v", false, "Verbose mode. Without this flag, the default behaviour only reports errors.")
+        flag.Parse()
+        flag.Usage = usage
+        if flag.NArg() != 2 {
+                usage()
+        }
+
+        var port int = *portPtr;
+        verbose = *verbosePtr;
+
+        root, _ := filepath.Abs(flag.Arg(0))
+        packageRoot := flag.Arg(1)
+
+        setupMappings(root, packageRoot, port);
+
+        http.ListenAndServe(fmt.Sprintf(":%v", port), nil)
 }