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// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/

// Test of echo command.  Run with: go test gopl.io/ch11/echo

//!+
package main

import (
    "bytes"
    "fmt"
    "testing"
)

func TestEcho(t *testing.T) {
    var tests = []struct {
        newline bool
        sep     string
        args    []string
        want    string
    }{
        {true, "", []string{}, "\n"},
        {false, "", []string{}, ""},
        {true, "\t", []string{"one", "two", "three"}, "one\ttwo\tthree\n"},
        {true, ",", []string{"a", "b", "c"}, "a,b,c\n"},
        {false, ":", []string{"1", "2", "3"}, "1:2:3"},
    }

    for _, test := range tests {
        descr := fmt.Sprintf("echo(%v, %q, %q)",
            test.newline, test.sep, test.args)

        out = new(bytes.Buffer) // captured output
        if err := echo(test.newline, test.sep, test.args); err != nil {
            t.Errorf("%s failed: %v", descr, err)
            continue
        }
        got := out.(*bytes.Buffer).String()
        if got != test.want {
            t.Errorf("%s = %q, want %q", descr, got, test.want)
        }
    }
}

//!-