termdash/widgets/linechart/axes/label_test.go

271 lines
6.7 KiB
Go

// Copyright 2019 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package axes
import (
"image"
"testing"
"github.com/kylelemons/godebug/pretty"
)
func TestYLabels(t *testing.T) {
const nonZeroDecimals = 2
tests := []struct {
desc string
min float64
max float64
cvsHeight int
labelWidth int
want []*Label
wantErr bool
}{
{
desc: "fails when canvas is too small",
min: 0,
max: 1,
cvsHeight: 1,
labelWidth: 4,
wantErr: true,
},
{
desc: "fails when labelWidth is too small",
min: 0,
max: 1,
cvsHeight: 2,
labelWidth: 0,
wantErr: true,
},
{
desc: "works when there are no data points",
min: 0,
max: 0,
cvsHeight: 2,
labelWidth: 1,
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
},
},
{
desc: "works when min equals max",
min: 5,
max: 5,
cvsHeight: 2,
labelWidth: 1,
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(2.88, nonZeroDecimals), image.Point{0, 0}},
},
},
{
desc: "only two rows on the canvas, labels min and max",
min: 0,
max: 5,
cvsHeight: 2,
labelWidth: 1,
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(2.88, nonZeroDecimals), image.Point{0, 0}},
},
},
{
desc: "aligns labels to the right",
min: 0,
max: 5,
cvsHeight: 2,
labelWidth: 5,
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{4, 1}},
{NewValue(2.88, nonZeroDecimals), image.Point{1, 0}},
},
},
{
desc: "multiple labels, last on the top",
min: 0,
max: 5,
cvsHeight: 9,
labelWidth: 1,
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 8}},
{NewValue(2.4, nonZeroDecimals), image.Point{0, 4}},
{NewValue(4.8, nonZeroDecimals), image.Point{0, 0}},
},
},
{
desc: "multiple labels, last on top-1",
min: 0,
max: 5,
cvsHeight: 10,
labelWidth: 1,
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 9}},
{NewValue(2.08, nonZeroDecimals), image.Point{0, 5}},
{NewValue(4.16, nonZeroDecimals), image.Point{0, 1}},
},
},
}
for _, tc := range tests {
t.Run(tc.desc, func(t *testing.T) {
scale, err := NewYScale(tc.min, tc.max, tc.cvsHeight, nonZeroDecimals)
if err != nil {
t.Fatalf("NewYScale => unexpected error: %v", err)
}
t.Logf("scale step: %v", scale.Step.Rounded)
got, err := yLabels(scale, tc.labelWidth)
if (err != nil) != tc.wantErr {
t.Errorf("yLabels => unexpected error: %v, wantErr: %v", err, tc.wantErr)
}
if err != nil {
return
}
if diff := pretty.Compare(tc.want, got); diff != "" {
t.Errorf("yLabels => unexpected diff (-want, +got):\n%s", diff)
}
})
}
}
func TestXLabels(t *testing.T) {
const nonZeroDecimals = 2
tests := []struct {
desc string
numPoints int
axisWidth int
axisStart image.Point
want []*Label
wantErr bool
}{
{
desc: "only one point",
numPoints: 1,
axisWidth: 1,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
},
},
{
desc: "two points, only one label fits",
numPoints: 2,
axisWidth: 1,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
},
},
{
desc: "two points, two labels fit exactly",
numPoints: 2,
axisWidth: 5,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(1, nonZeroDecimals), image.Point{4, 1}},
},
},
{
desc: "labels are placed according to axisStart",
numPoints: 2,
axisWidth: 5,
axisStart: image.Point{3, 5},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{3, 5}},
{NewValue(1, nonZeroDecimals), image.Point{7, 5}},
},
},
{
desc: "skip to next value exhausts the space completely",
numPoints: 11,
axisWidth: 4,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
},
},
{
desc: "second label doesn't fit due to its length",
numPoints: 100,
axisWidth: 5,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
},
},
{
desc: "two points, two labels, more space than minSpacing so end label adjusted",
numPoints: 2,
axisWidth: 6,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(1, nonZeroDecimals), image.Point{5, 1}},
},
},
{
desc: "at most as many labels as there are points",
numPoints: 2,
axisWidth: 100,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(1, nonZeroDecimals), image.Point{98, 1}},
},
},
{
desc: "some labels in the middle",
numPoints: 4,
axisWidth: 100,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(1, nonZeroDecimals), image.Point{31, 1}},
{NewValue(2, nonZeroDecimals), image.Point{62, 1}},
{NewValue(3, nonZeroDecimals), image.Point{94, 1}},
},
},
{
desc: "more points than pixels",
numPoints: 100,
axisWidth: 6,
axisStart: image.Point{0, 1},
want: []*Label{
{NewValue(0, nonZeroDecimals), image.Point{0, 1}},
{NewValue(72, nonZeroDecimals), image.Point{4, 1}},
},
},
}
for _, tc := range tests {
t.Run(tc.desc, func(t *testing.T) {
scale, err := NewXScale(tc.numPoints, tc.axisWidth, nonZeroDecimals)
if err != nil {
t.Fatalf("NewXScale => unexpected error: %v", err)
}
t.Logf("scale step: %v", scale.Step.Rounded)
got, err := xLabels(scale, tc.axisStart)
if (err != nil) != tc.wantErr {
t.Errorf("xLabels => unexpected error: %v, wantErr: %v", err, tc.wantErr)
}
if err != nil {
return
}
if diff := pretty.Compare(tc.want, got); diff != "" {
t.Errorf("xLabels => unexpected diff (-want, +got):\n%s", diff)
}
})
}
}