`1` ```exercism fetch go matrix ```

#### matrix_test.go

 ```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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266``` ```// For the Matrix exercise in Go you have to do a few things not mentioned // in the README. // // 1. You must implement a constructor and methods Rows() and Cols() as // described in the README, but Rows() and Cols must return results that // are independent from the original matrix. That is, you should be able // to do as you please with the results without affecting the matrix. // // 2. You must implement a method Set(row, col, val) for setting a matrix // element. // // 3. As usual in Go, you must detect and return error conditions. package matrix import ( "reflect" "testing" ) var tests = []struct { in string ok bool rows [][]int cols [][]int }{ {"1 2\n10 20", true, [][]int{ {1, 2}, {10, 20}, }, [][]int{ {1, 10}, {2, 20}, }, }, {"9 7\n8 6", true, [][]int{ {9, 7}, {8, 6}, }, [][]int{ {9, 8}, {7, 6}, }, }, {"9 8 7\n19 18 17", true, [][]int{ {9, 8, 7}, {19, 18, 17}, }, [][]int{ {9, 19}, {8, 18}, {7, 17}, }, }, {"1 4 9\n16 25 36", true, [][]int{ {1, 4, 9}, {16, 25, 36}, }, [][]int{ {1, 16}, {4, 25}, {9, 36}, }, }, {"1 2 3\n4 5 6\n7 8 9\n 8 7 6", true, [][]int{ {1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {8, 7, 6}, }, [][]int{ {1, 4, 7, 8}, {2, 5, 8, 7}, {3, 6, 9, 6}, }, }, {"89 1903 3\n18 3 1\n9 4 800", true, [][]int{ {89, 1903, 3}, {18, 3, 1}, {9, 4, 800}, }, [][]int{ {89, 18, 9}, {1903, 3, 4}, {3, 1, 800}, }, }, {"1 2 3", // valid, 1 row, 3 columns true, [][]int{ {1, 2, 3}, }, [][]int{ {1}, {2}, {3}, }, }, {"1\n2\n3", // valid, 3 rows, 1 column true, [][]int{ {1}, {2}, {3}, }, [][]int{ {1, 2, 3}, }, }, {"0", // valid, 1 row, 1 column true, [][]int{ {0}, }, [][]int{ {0}, }, }, {"9223372036854775808", false, nil, nil}, // overflows int64 {"1 2\n10 20 30", false, nil, nil}, // uneven rows {"\n3 4\n5 6", false, nil, nil}, // first row empty {"1 2\n\n5 6", false, nil, nil}, // middle row empty {"1 2\n3 4\n", false, nil, nil}, // last row empty {"2.7", false, nil, nil}, // non-int {"cat", false, nil, nil}, // non-numeric // undefined // {"\n\n", // valid?, 3 rows, 0 columns // {"", // valid?, 0 rows, 0 columns } func TestNew(t *testing.T) { for _, test := range tests { m, err := New(test.in) switch { case err != nil: var _ error = err if test.ok { t.Fatalf("New(%q) returned error %q. Error not expected", test.in, err) } case !test.ok: t.Fatalf("New(%q) = %v, %v. Expected non-nil error.", test.in, m, err) case m == nil: t.Fatalf("New(%q) = %v, want non-nil *Matrix", test.in, m) } } } func TestRows(t *testing.T) { for _, test := range tests { if !test.ok { continue } m, err := New(test.in) if err != nil { t.Skip("Need working New for TestRows") } r := m.Rows() if len(r) == 0 && len(test.rows) == 0 { continue // agreement, and nothing more to test } if !reflect.DeepEqual(r, test.rows) { t.Fatalf("New(%q).Rows() = %v, want %v", test.in, r, test.rows) } if len(r[0]) == 0 { continue // not currently in test data, but anyway } r[0][0]++ if !reflect.DeepEqual(m.Rows(), test.rows) { t.Fatalf("Matrix.Rows() returned slice based on Matrix " + "representation. Want independent copy of element data.") } } } func TestCols(t *testing.T) { for _, test := range tests { if !test.ok { continue } m, err := New(test.in) if err != nil { t.Skip("Need working New for TestCols") } c := m.Cols() if len(c) == 0 && len(test.cols) == 0 { continue // agreement, and nothing more to test } if !reflect.DeepEqual(c, test.cols) { t.Fatalf("New(%q).Cols() = %v, want %v", test.in, c, test.cols) } if len(c[0]) == 0 { continue // not currently in test data, but anyway } c[0][0]++ if !reflect.DeepEqual(m.Cols(), test.cols) { t.Fatalf("Matrix.Cols() returned slice based on Matrix " + "representation. Want independent copy of element data.") } } } func TestSet(t *testing.T) { s := "1 2 3\n4 5 6\n7 8 9" m, err := New(s) if err != nil { t.Skip("Need working New for TestSet") } xr := [][]int{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}} if !reflect.DeepEqual(m.Rows(), xr) { t.Skip("Need working Rows for TestSet") } xc := [][]int{{1, 4, 7}, {2, 5, 8}, {3, 6, 9}} if !reflect.DeepEqual(m.Cols(), xc) { t.Skip("Need working Cols for TestSet") } // test each corner, each side, and an interior element for r := 0; r < 3; r++ { for c := 0; c < 3; c++ { m, _ = New(s) val := 10 + r*3 + c if ok := m.Set(r, c, val); !ok { t.Fatalf("Matrix(%q).Set(%d, %d, %d) returned !ok, want ok.", s, r, c, val) } xr = [][]int{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}} xc = [][]int{{1, 4, 7}, {2, 5, 8}, {3, 6, 9}} xr[r][c] = val xc[c][r] = val if res := m.Rows(); !reflect.DeepEqual(res, xr) { t.Fatalf("Matrix(%q).Set(%d, %d, %d), Rows() = %v, want %v", s, r, c, val, res, xr) } if res := m.Cols(); !reflect.DeepEqual(res, xc) { t.Fatalf("Matrix(%q).Set(%d, %d, %d), Cols() = %v, want %v", s, r, c, val, res, xc) } } } // test 1 and 2 off each corner and side m, _ = New(s) for _, r := range []int{-2, -1, 0, 3, 4} { for _, c := range []int{-2, -1, 0, 3, 4} { if r == 0 && c == 0 { continue } if ok := m.Set(r, c, 0); ok { t.Fatalf("Matrix(%q).Set(%d, %d, 0) = ok, want !ok", s, r, c) } } } } ```