Add http golang

src/SUMMARY.md

@@ -5,6 +5,7 @@
 - [Dev](./dev/main.md)
 
   - [Golang](./dev/golang/main.md)
+    - [http](./dev/golang/http.md)
     - [Packages](./dev/golang/packages.md)
     - [Testing](./dev/golang/testing.md)
   - [Elixir](./dev/elixir/main.md)

src/dev/golang/http.md

@@ -0,0 +1,67 @@
+# http package stuff
+
+## HTTP Status Code
+
+Do not use number directly.
+
+Don't do this
+
+```golang
+w.WriteHeader(404)
+```
+
+Do this
+
+```golang
+w.WriteHeader(http.StatusNotFound)
+```
+
+## Error message
+
+```golang
+http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
+```
+
+## Flusher
+
+A [Flusher](https://pkg.go.dev/net/http#Flusher) can be used to allow an HTTP handler to flush buffered data to the client.
+
+```golang
+package main
+
+import (
+    "fmt"
+    "io"
+    "net/http"
+    "time"
+)
+
+func main() {
+    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+        ended := make(chan bool)
+        f, flushable := w.(http.Flusher)
+        if flushable {
+            go func() {
+                ticker := time.NewTicker(1 * time.Second)
+                for {
+                    select {
+                    case <-ticker.C:
+                        fmt.Println("debug")
+                        io.WriteString(w, "#")
+                        f.Flush()
+                    case <-ended:
+                        return
+                    case <-r.Context().Done():
+                        return
+                    }
+                }
+            }()
+        }
+        time.Sleep(5 * time.Second)
+        ended <- true
+        w.Write([]byte("ok"))
+    })
+
+    http.ListenAndServe(":8080", nil)
+}
+```