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| 1 | +module TaskSeq.Tests.MaxMin |
| 2 | + |
| 3 | +open System |
| 4 | + |
| 5 | +open Xunit |
| 6 | +open FsUnit.Xunit |
| 7 | + |
| 8 | +open FSharp.Control |
| 9 | + |
| 10 | +// |
| 11 | +// TaskSeq.max |
| 12 | +// TaskSeq.min |
| 13 | +// TaskSeq.maxBy |
| 14 | +// TaskSeq.minBy |
| 15 | +// TaskSeq.maxByAsync |
| 16 | +// TaskSeq.minByAsync |
| 17 | +// |
| 18 | + |
| 19 | +type MinMax = |
| 20 | + | Max = 0 |
| 21 | + | Min = 1 |
| 22 | + | MaxBy = 2 |
| 23 | + | MinBy = 3 |
| 24 | + | MaxByAsync = 4 |
| 25 | + | MinByAsync = 5 |
| 26 | + |
| 27 | +module MinMax = |
| 28 | + let getFunction = |
| 29 | + function |
| 30 | + | MinMax.Max -> TaskSeq.max |
| 31 | + | MinMax.Min -> TaskSeq.min |
| 32 | + | MinMax.MaxBy -> TaskSeq.maxBy id |
| 33 | + | MinMax.MinBy -> TaskSeq.minBy id |
| 34 | + | MinMax.MaxByAsync -> TaskSeq.maxByAsync Task.fromResult |
| 35 | + | MinMax.MinByAsync -> TaskSeq.minByAsync Task.fromResult |
| 36 | + | _ -> failwith "impossible" |
| 37 | + |
| 38 | + let getByFunction = |
| 39 | + function |
| 40 | + | MinMax.MaxBy -> TaskSeq.maxBy |
| 41 | + | MinMax.MinBy -> TaskSeq.minBy |
| 42 | + | MinMax.MaxByAsync -> fun by -> TaskSeq.maxByAsync (by >> Task.fromResult) |
| 43 | + | MinMax.MinByAsync -> fun by -> TaskSeq.minByAsync (by >> Task.fromResult) |
| 44 | + | _ -> failwith "impossible" |
| 45 | + |
| 46 | + let getAll () = |
| 47 | + [ MinMax.Max; MinMax.Min; MinMax.MaxBy; MinMax.MinBy; MinMax.MaxByAsync; MinMax.MinByAsync ] |
| 48 | + |> List.map getFunction |
| 49 | + |
| 50 | + let getAllMin () = |
| 51 | + [ MinMax.Min; MinMax.MinBy; MinMax.MinByAsync ] |
| 52 | + |> List.map getFunction |
| 53 | + |
| 54 | + let getAllMax () = |
| 55 | + [ MinMax.Max; MinMax.MaxBy; MinMax.MaxByAsync ] |
| 56 | + |> List.map getFunction |
| 57 | + |
| 58 | + let isMin = |
| 59 | + function |
| 60 | + | MinMax.Min |
| 61 | + | MinMax.MinBy |
| 62 | + | MinMax.MinByAsync -> true |
| 63 | + | _ -> false |
| 64 | + |
| 65 | + let isMax = isMin >> not |
| 66 | + |
| 67 | + |
| 68 | +type AllMinMaxFunctions() as this = |
| 69 | + inherit TheoryData<MinMax>() |
| 70 | + |
| 71 | + do |
| 72 | + this.Add MinMax.Max |
| 73 | + this.Add MinMax.Min |
| 74 | + this.Add MinMax.MaxBy |
| 75 | + this.Add MinMax.MinBy |
| 76 | + this.Add MinMax.MaxByAsync |
| 77 | + this.Add MinMax.MinByAsync |
| 78 | + |
| 79 | +type JustMin() as this = |
| 80 | + inherit TheoryData<MinMax>() |
| 81 | + |
| 82 | + do |
| 83 | + this.Add MinMax.Min |
| 84 | + this.Add MinMax.MinBy |
| 85 | + this.Add MinMax.MinByAsync |
| 86 | + |
| 87 | +type JustMax() as this = |
| 88 | + inherit TheoryData<MinMax>() |
| 89 | + |
| 90 | + do |
| 91 | + this.Add MinMax.Max |
| 92 | + this.Add MinMax.MaxBy |
| 93 | + this.Add MinMax.MaxByAsync |
| 94 | + |
| 95 | +type JustMinMaxBy() as this = |
| 96 | + inherit TheoryData<MinMax>() |
| 97 | + |
| 98 | + do |
| 99 | + this.Add MinMax.MaxBy |
| 100 | + this.Add MinMax.MinBy |
| 101 | + this.Add MinMax.MaxByAsync |
| 102 | + this.Add MinMax.MinByAsync |
| 103 | + |
| 104 | +module EmptySeq = |
| 105 | + [<Theory; ClassData(typeof<AllMinMaxFunctions>)>] |
| 106 | + let ``Null source raises ArgumentNullException`` (minMaxType: MinMax) = |
| 107 | + let minMax = MinMax.getFunction minMaxType |
| 108 | + |
| 109 | + assertNullArg <| fun () -> minMax (null: TaskSeq<int>) |
| 110 | + |
| 111 | + [<Theory; ClassData(typeof<TestEmptyVariants>)>] |
| 112 | + let ``Empty sequence raises ArgumentException`` variant = |
| 113 | + let test minMax = |
| 114 | + let data = Gen.getEmptyVariant variant |
| 115 | + |
| 116 | + fun () -> minMax data |> Task.ignore |
| 117 | + |> should throwAsyncExact typeof<ArgumentException> |
| 118 | + |
| 119 | + for minMax in MinMax.getAll () do |
| 120 | + test minMax |
| 121 | + |
| 122 | +module Functionality = |
| 123 | + [<Fact>] |
| 124 | + let ``TaskSeq-max should return maximum`` () = task { |
| 125 | + let ts = [ 'A' .. 'Z' ] |> TaskSeq.ofList |
| 126 | + let! max = TaskSeq.max ts |
| 127 | + max |> should equal 'Z' |
| 128 | + } |
| 129 | + |
| 130 | + [<Fact>] |
| 131 | + let ``TaskSeq-maxBy should return maximum of input, not the projection`` () = task { |
| 132 | + let ts = [ 'A' .. 'Z' ] |> TaskSeq.ofList |
| 133 | + let! max = TaskSeq.maxBy id ts |
| 134 | + max |> should equal 'Z' |
| 135 | + |
| 136 | + let ts = [ 1..10 ] |> TaskSeq.ofList |
| 137 | + let! max = TaskSeq.maxBy (~-) ts |
| 138 | + max |> should equal 1 // as negated, -1 is highest, should not return projection, but original |
| 139 | + } |
| 140 | + |
| 141 | + [<Fact>] |
| 142 | + let ``TaskSeq-maxByAsync should return maximum of input, not the projection`` () = task { |
| 143 | + let ts = [ 'A' .. 'Z' ] |> TaskSeq.ofList |
| 144 | + let! max = TaskSeq.maxByAsync Task.fromResult ts |
| 145 | + max |> should equal 'Z' |
| 146 | + |
| 147 | + let ts = [ 1..10 ] |> TaskSeq.ofList |
| 148 | + let! max = TaskSeq.maxByAsync (fun x -> Task.fromResult -x) ts |
| 149 | + max |> should equal 1 // as negated, -1 is highest, should not return projection, but original |
| 150 | + } |
| 151 | + |
| 152 | + [<Fact>] |
| 153 | + let ``TaskSeq-min should return minimum`` () = task { |
| 154 | + let ts = [ 'A' .. 'Z' ] |> TaskSeq.ofList |
| 155 | + let! min = TaskSeq.min ts |
| 156 | + min |> should equal 'A' |
| 157 | + } |
| 158 | + |
| 159 | + [<Fact>] |
| 160 | + let ``TaskSeq-minBy should return minimum of input, not the projection`` () = task { |
| 161 | + let ts = [ 'A' .. 'Z' ] |> TaskSeq.ofList |
| 162 | + let! min = TaskSeq.minBy id ts |
| 163 | + min |> should equal 'A' |
| 164 | + |
| 165 | + let ts = [ 1..10 ] |> TaskSeq.ofList |
| 166 | + let! min = TaskSeq.minBy (~-) ts |
| 167 | + min |> should equal 10 // as negated, -10 is lowest, should not return projection, but original |
| 168 | + } |
| 169 | + |
| 170 | + [<Fact>] |
| 171 | + let ``TaskSeq-minByAsync should return minimum of input, not the projection`` () = task { |
| 172 | + let ts = [ 'A' .. 'Z' ] |> TaskSeq.ofList |
| 173 | + let! min = TaskSeq.minByAsync Task.fromResult ts |
| 174 | + min |> should equal 'A' |
| 175 | + |
| 176 | + let ts = [ 1..10 ] |> TaskSeq.ofList |
| 177 | + let! min = TaskSeq.minByAsync (fun x -> Task.fromResult -x) ts |
| 178 | + min |> should equal 10 // as negated, 1 is highest, should not return projection, but original |
| 179 | + } |
| 180 | + |
| 181 | + |
| 182 | +module Immutable = |
| 183 | + [<Theory; ClassData(typeof<TestImmTaskSeq>)>] |
| 184 | + let ``TaskSeq-max, maxBy, maxByAsync returns maximum`` variant = task { |
| 185 | + let ts = Gen.getSeqImmutable variant |
| 186 | + |
| 187 | + for max in MinMax.getAllMax () do |
| 188 | + let! max = max ts |
| 189 | + max |> should equal 10 |
| 190 | + } |
| 191 | + |
| 192 | + [<Theory; ClassData(typeof<TestImmTaskSeq>)>] |
| 193 | + let ``TaskSeq-min, minBy, minByAsync returns minimum`` variant = task { |
| 194 | + let ts = Gen.getSeqImmutable variant |
| 195 | + |
| 196 | + for min in MinMax.getAllMin () do |
| 197 | + let! min = min ts |
| 198 | + min |> should equal 1 |
| 199 | + } |
| 200 | + |
| 201 | + [<Theory; ClassData(typeof<TestImmTaskSeq>)>] |
| 202 | + let ``TaskSeq-maxBy, maxByAsync returns maximum after projection`` variant = task { |
| 203 | + let ts = Gen.getSeqImmutable variant |
| 204 | + let! max = ts |> TaskSeq.maxBy (fun x -> -x) |
| 205 | + max |> should equal 1 // because -1 maps to item '1' |
| 206 | + } |
| 207 | + |
| 208 | + |
| 209 | + [<Theory; ClassData(typeof<TestImmTaskSeq>)>] |
| 210 | + let ``TaskSeq-minBy, minByAsync returns minimum after projection`` variant = task { |
| 211 | + let ts = Gen.getSeqImmutable variant |
| 212 | + let! min = ts |> TaskSeq.minBy (fun x -> -x) |
| 213 | + min |> should equal 10 // because -10 maps to item 10 |
| 214 | + } |
| 215 | + |
| 216 | +module SideSeffects = |
| 217 | + [<Fact>] |
| 218 | + let ``TaskSeq-max, maxBy, maxByAsync prove we execute after-effects`` () = task { |
| 219 | + let mutable i = 0 |
| 220 | + |
| 221 | + let ts = taskSeq { |
| 222 | + i <- i + 1 |
| 223 | + i <- i + 1 |
| 224 | + yield i // 2 |
| 225 | + i <- i + 1 |
| 226 | + yield i // 3 |
| 227 | + yield i + 1 // 4 |
| 228 | + i <- i + 1 // we should get here |
| 229 | + } |
| 230 | + |
| 231 | + do! ts |> TaskSeq.max |> Task.map (should equal 4) |
| 232 | + do! ts |> TaskSeq.maxBy (~-) |> Task.map (should equal 6) // next iteration & negation "-6" maps to "6" |
| 233 | + |
| 234 | + do! |
| 235 | + ts |
| 236 | + |> TaskSeq.maxByAsync Task.fromResult |
| 237 | + |> Task.map (should equal 12) // no negation |
| 238 | + |
| 239 | + i |> should equal 12 |
| 240 | + } |
| 241 | + |
| 242 | + [<Fact>] |
| 243 | + let ``TaskSeq-min, minBy, minByAsync prove we execute after-effects test`` () = task { |
| 244 | + let mutable i = 0 |
| 245 | + |
| 246 | + let ts = taskSeq { |
| 247 | + i <- i + 1 |
| 248 | + i <- i + 1 |
| 249 | + yield i // 2 |
| 250 | + i <- i + 1 |
| 251 | + yield i // 3 |
| 252 | + yield i + 1 // 4 |
| 253 | + i <- i + 1 // we should get here |
| 254 | + } |
| 255 | + |
| 256 | + do! ts |> TaskSeq.min |> Task.map (should equal 2) |
| 257 | + do! ts |> TaskSeq.minBy (~-) |> Task.map (should equal 8) // next iteration & negation |
| 258 | + |
| 259 | + do! |
| 260 | + ts |
| 261 | + |> TaskSeq.minByAsync Task.fromResult |
| 262 | + |> Task.map (should equal 10) // no negation |
| 263 | + |
| 264 | + i |> should equal 12 |
| 265 | + } |
| 266 | + |
| 267 | + |
| 268 | + [<Theory; ClassData(typeof<JustMax>)>] |
| 269 | + let ``TaskSeq-max with sequence that changes length`` (minMax: MinMax) = task { |
| 270 | + let max = MinMax.getFunction minMax |
| 271 | + let mutable i = 0 |
| 272 | + |
| 273 | + let ts = taskSeq { |
| 274 | + i <- i + 10 |
| 275 | + yield! [ 1..i ] |
| 276 | + } |
| 277 | + |
| 278 | + do! max ts |> Task.map (should equal 10) |
| 279 | + do! max ts |> Task.map (should equal 20) // mutable state dangers!! |
| 280 | + do! max ts |> Task.map (should equal 30) // id |
| 281 | + } |
| 282 | + |
| 283 | + [<Theory; ClassData(typeof<JustMin>)>] |
| 284 | + let ``TaskSeq-min with sequence that changes length`` (minMax: MinMax) = task { |
| 285 | + let min = MinMax.getFunction minMax |
| 286 | + let mutable i = 0 |
| 287 | + |
| 288 | + let ts = taskSeq { |
| 289 | + i <- i + 10 |
| 290 | + yield! [ 1..i ] |
| 291 | + } |
| 292 | + |
| 293 | + do! min ts |> Task.map (should equal 1) |
| 294 | + do! min ts |> Task.map (should equal 1) // same min after changing state |
| 295 | + do! min ts |> Task.map (should equal 1) // id |
| 296 | + } |
| 297 | + |
| 298 | + [<Theory; ClassData(typeof<JustMinMaxBy>)>] |
| 299 | + let ``TaskSeq-minBy, maxBy with sequence that changes length`` (minMax: MinMax) = task { |
| 300 | + let mutable i = 0 |
| 301 | + |
| 302 | + let ts = taskSeq { |
| 303 | + i <- i + 10 |
| 304 | + yield! [ 1..i ] |
| 305 | + } |
| 306 | + |
| 307 | + let test minMaxFn v = |
| 308 | + if MinMax.isMin minMax then |
| 309 | + // this ensures the "min" version behaves like the "max" version |
| 310 | + minMaxFn (~-) ts |> Task.map (should equal v) |
| 311 | + else |
| 312 | + minMaxFn id ts |> Task.map (should equal v) |
| 313 | + |
| 314 | + do! test (MinMax.getByFunction minMax) 10 |
| 315 | + do! test (MinMax.getByFunction minMax) 20 |
| 316 | + do! test (MinMax.getByFunction minMax) 30 |
| 317 | + } |
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