feat: port table-printers from influxdb (#145)

pkg/template/diff_printer_test.go

@@ -0,0 +1,67 @@
+package template_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/influxdata/influx-cli/v2/pkg/template"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDiffPrinter_Empty(t *testing.T) {
+	t.Parallel()
+
+	out := bytes.Buffer{}
+	printer := template.NewDiffPrinter(&out, false, true).
+		Title("Example").
+		SetHeaders("Wow", "Such", "A", "Fancy", "Printer")
+
+	printer.Render()
+	require.Empty(t, out.String())
+}
+
+func TestDiffPrinter(t *testing.T) {
+	t.Parallel()
+
+	out := bytes.Buffer{}
+	printer := template.NewDiffPrinter(&out, false, true).
+		Title("Example").
+		SetHeaders("Wow", "Such", "A", "Fancy", "Printer")
+
+	// Add
+	printer.AppendDiff(nil, []string{"A", "B", "C", "D", "E"})
+
+	// No change
+	printer.Append([]string{"foo", "bar", "baz", "qux", "wat"})
+
+	// Replace
+	printer.AppendDiff(
+		[]string{"1", "200000000000000", "3", "4", "5"},
+		[]string{"9", "8", "7", "6", "5"},
+	)
+
+	// Remove
+	printer.AppendDiff([]string{"x y", "z x", "x y z", "", "y z"}, nil)
+
+	printer.Render()
+	expected := `EXAMPLE    +add | -remove | unchanged
++-----+-----+-----------------+-------+-------+---------+
+| +/- | WOW |      SUCH       |   A   | FANCY | PRINTER |
++-----+-----+-----------------+-------+-------+---------+
+| +   | A   | B               | C     | D     | E       |
++-----+-----+-----------------+-------+-------+---------+
+|     | foo | bar             | baz   | qux   | wat     |
++-----+-----+-----------------+-------+-------+---------+
++-----+-----+-----------------+-------+-------+---------+
+| -   |   1 | 200000000000000 |     3 |     4 |       5 |
++-----+-----+-----------------+-------+-------+---------+
+| +   |   9 |               8 |     7 |     6 |       5 |
++-----+-----+-----------------+-------+-------+---------+
++-----+-----+-----------------+-------+-------+---------+
+| -   | x y | z x             | x y z |       | y z     |
++-----+-----+-----------------+-------+-------+---------+
+|                                       TOTAL |    3    |
++-----+-----+-----------------+-------+-------+---------+
+`
+	require.Equal(t, expected, out.String())
+}