striped-background/index.test.ts at master · downace/striped-background · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
import stripedBackground, { AngleString } from "./index";

describe("stripedBackground", () => {
  test("empty pattern", () => {
    expect(stripedBackground([])).toEqual({});
  });

  test("single color pattern", () => {
    expect(stripedBackground([["rgba(4, 3, 2, 1)", 30]])).toEqual({
      backgroundColor: "rgba(4, 3, 2, 1)",
    });
  });

  test("default angle and offset", () => {
    expect(
      stripedBackground([
        ["red", 10],
        ["tan", 10],
      ]),
    ).toEqual({
      backgroundImage:
        "linear-gradient(45deg, red 10px, tan 10px, tan 20px, red 20px, red 30px, tan 30px)",
      backgroundPosition: "top 0px left 0px",
      backgroundSize: "28.2843px 28.2843px",
    });
  });

  test("invalid angle string", () => {
    expect(() =>
      stripedBackground(
        [
          ["red", 10],
          ["tan", 10],
        ],
        "invalid" as any,
      ),
    ).toThrow("Unable to parse angle: invalid");
  });

  test("invalid angle unit", () => {
    expect(() =>
      stripedBackground(
        [
          ["red", 10],
          ["tan", 10],
        ],
        "45degrees" as any,
      ),
    ).toThrow("Unable to parse angle: 45degrees");
  });

  test.each<{
    angle: number | AngleString;
    expAngle: string;
    expSize: string;
  }>([
    { angle: 30, expAngle: "30deg", expSize: "40px 23.094px" },
    { angle: "30", expAngle: "30deg", expSize: "40px 23.094px" },
    { angle: "30deg", expAngle: "30deg", expSize: "40px 23.094px" },
    { angle: "0.1turn", expAngle: "0.1turn", expSize: "34.026px 24.7214px" },
    { angle: "0.5rad", expAngle: "0.5rad", expSize: "41.7166px 22.7899px" },
    { angle: "30grad", expAngle: "30grad", expSize: "44.0538px 22.4465px" },
  ])("different angle formats", ({ angle, expAngle, expSize }) => {
    expect(
      stripedBackground(
        [
          ["red", 10],
          ["tan", 10],
        ],
        angle,
      ),
    ).toEqual({
      backgroundImage: `linear-gradient(${expAngle}, red 9.5px, tan 10.5px, tan 19.5px, red 20.5px, red 29.5px, tan 30.5px)`,
      backgroundPosition: "top 0px left 0px",
      backgroundSize: expSize,
    });
  });

  test.each([
    { angle: -390, expAngle: "-30deg", expSize: "40px 23.094px" },
    { angle: -330, expAngle: "30deg", expSize: "40px 23.094px" },
    { angle: -210, expAngle: "150deg", expSize: "40px 23.094px" },
    { angle: -150, expAngle: "-150deg", expSize: "40px 23.094px" },
    { angle: -30, expAngle: "-30deg", expSize: "40px 23.094px" },
    { angle: 30, expAngle: "30deg", expSize: "40px 23.094px" },
    { angle: 150, expAngle: "150deg", expSize: "40px 23.094px" },
    { angle: 210, expAngle: "-150deg", expSize: "40px 23.094px" },
    { angle: 330, expAngle: "-30deg", expSize: "40px 23.094px" },
    { angle: 390, expAngle: "30deg", expSize: "40px 23.094px" },
  ])("angle normalization", ({ angle, expAngle, expSize }) => {
    expect(
      stripedBackground(
        [
          ["red", 10],
          ["tan", 10],
        ],
        angle,
      ),
    ).toEqual({
      backgroundImage: `linear-gradient(${expAngle}, red 9.5px, tan 10.5px, tan 19.5px, red 20.5px, red 29.5px, tan 30.5px)`,
      backgroundPosition: "top 0px left 0px",
      backgroundSize: expSize,
    });
  });

  test.each([
    { angle: -180, expSize: "1px 20px" },
    { angle: -135, expSize: "28.2843px 28.2843px" },
    { angle: -90, expSize: "20px 1px" },
    { angle: -45, expSize: "28.2843px 28.2843px" },
    { angle: 0, expSize: "1px 20px" },
    { angle: 45, expSize: "28.2843px 28.2843px" },
    { angle: 90, expSize: "20px 1px" },
    { angle: 135, expSize: "28.2843px 28.2843px" },
    { angle: 180, expSize: "1px 20px" },
  ])("angle is multiple of 45", ({ angle, expSize }) => {
    expect(
      stripedBackground(
        [
          ["red", 10],
          ["tan", 10],
        ],
        angle,
      ),
    ).toEqual({
      backgroundImage: `linear-gradient(${angle}deg, red 10px, tan 10px, tan 20px, red 20px, red 30px, tan 30px)`,
      backgroundPosition: "top 0px left 0px",
      backgroundSize: expSize,
    });
  });

  test("complex pattern", () => {
    expect(
      stripedBackground(
        [
          ["red", 2],
          ["yellow", 4],
          ["green", 8],
          ["blue", 16],
        ],
        0,
      ),
    ).toEqual({
      backgroundImage: `linear-gradient(0deg, red 2px, yellow 2px, yellow 6px, green 6px, green 14px, blue 14px, blue 30px, red 30px, red 32px, yellow 32px, yellow 36px, green 36px, green 44px, blue 44px)`,
      backgroundPosition: "top 0px left 0px",
      backgroundSize: "1px 30px",
    });
  });

  test.each([
    { offset: 0, expPosition: "top 0px left 0px" },
    { offset: 15, expPosition: "top -10.6066px left 10.6066px" },
    { offset: 20, expPosition: "top 0px left 0px" },
    { offset: 25, expPosition: "top -3.53553px left 3.53553px" },
  ])("offset", ({ offset, expPosition }) => {
    expect(
      stripedBackground(
        [
          ["red", 4],
          ["tan", 16],
        ],
        45,
        offset,
      ),
    ).toEqual({
      backgroundImage: `linear-gradient(45deg, red 4px, tan 4px, tan 20px, red 20px, red 24px, tan 24px)`,
      backgroundPosition: expPosition,
      backgroundSize: "28.2843px 28.2843px",
    });
  });

  test("precise angle", () => {
    expect(
      stripedBackground(
        [
          ["red", 4],
          ["tan", 16],
        ],
        "7.068583470577034rad", // 360 + 45 degrees
      ),
    ).toEqual({
      backgroundImage: `linear-gradient(0.7853981633974474rad, red 4px, tan 4px, tan 20px, red 20px, red 24px, tan 24px)`,
      backgroundPosition: "top 0px left 0px",
      backgroundSize: "28.2843px 28.2843px",
    });
  });
});