Add demo GIF using vhs and make

cmd/taint/Makefile

@@ -0,0 +1,7 @@
+.PHONY: install
+install:
+	@go build -o $(shell go env GOPATH)/bin/taint .
+
+.PHONY: vhs
+vhs:
+	@vhs ./vhs/demo.tape

cmd/taint/example/main.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"database/sql"
+	"net/http"
+)
+
+func handle(db *sql.DB, q string) {
+	db.Query(q) // want "potential sql injection"
+}
+
+func business(db *sql.DB, q *string) error {
+	handle(db, *q)
+	return nil
+}
+
+func main() {
+	db, _ := sql.Open("sqlite3", ":memory:")
+
+	mux := http.NewServeMux()
+
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		user := r.URL.Query()["query"]
+		userValue := user[0]
+		business(db, &userValue)
+	})
+
+	err := http.ListenAndServe(":8080", mux)
+	if err != nil {
+		panic(err)
+	}
+}

cmd/taint/main.go

@@ -31,7 +31,7 @@ var (
 	styleNumber   = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("69"))
 	styleArgument = lipgloss.NewStyle().Foreground(lipgloss.Color("68"))
 	styleFlag     = lipgloss.NewStyle().Foreground(lipgloss.Color("66"))
-	styleCommand  = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("55"))
+	styleCommand  = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("62"))
 )
 
 var (
@@ -243,7 +243,10 @@ func (c commands) eval(ctx context.Context, bt *bufio.Writer, input string) erro
 		}
 	}
 
-	return fmt.Errorf("unknown command: %q", cmdName)
+	bt.WriteString("unknown command: " + cmdName + "\n")
+	bt.Flush()
+
+	return nil
 }
 
 var builtinCommandExit = &command{

cmd/taint/vhs/demo.tape

@@ -0,0 +1,75 @@
+Output ./vhs/demo.gif
+
+Set Margin 20
+Set MarginFill "#ffffff"
+Set BorderRadius 10
+
+Set FontSize 20
+Set Width 1200
+Set Height 600
+
+Type "taint"
+
+Sleep 500ms
+
+Enter
+
+Sleep 3s
+
+Type "load ./example"
+
+Sleep 500ms
+
+Enter
+
+Sleep 2s
+
+Type "n"
+
+Tab@500ms 2
+
+Sleep 500ms
+
+Enter
+
+Sleep 2s
+
+Type "p"
+
+Tab@500ms 2
+
+Enter
+
+Sleep 5s
+
+Type "cg"
+
+Sleep 1s
+
+Enter
+
+Sleep 5s
+
+Type "callpath (*database/sql.DB).Query"
+
+Sleep 500ms
+
+Enter
+
+Sleep 3s
+
+Type "check *net/http.Request (*database/sql.DB).Query"
+
+Sleep 500ms
+
+Enter
+
+Sleep 5s
+
+Type "ex"
+
+Tab@500ms 2
+
+Enter
+
+Sleep 5s