[JS/TS] Added missing ICollection helpers

src/Fable.Cli/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 * [Rust] Fixed derived traits mapping (by @ncave)
+* [JS/TS] Added missing ICollection helpers (#3914) (by @ncave)
 
 ## 4.23.0 - 2024-10-28
 

src/Fable.Transforms/Replacements.fs

@@ -1790,6 +1790,10 @@ let injectIndexOfArgs com ctx r genArgs args =
 
     injectArg com ctx r "Array" "indexOf" genArgs args
 
+let copyToArray (com: ICompiler) r t (i: CallInfo) args =
+    Helper.LibCall(com, "Util", "copyToArray", t, args, i.SignatureArgTypes, genArgs = i.GenericArgs, ?loc = r)
+    |> Some
+
 let resizeArrays (com: ICompiler) (ctx: Context) r (t: Type) (i: CallInfo) (thisArg: Expr option) (args: Expr list) =
     match i.CompiledName, thisArg, args with
     | ".ctor", _, [] -> makeResizeArray (getElementType t) [] |> Some
@@ -1803,6 +1807,13 @@ let resizeArrays (com: ICompiler) (ctx: Context) r (t: Type) (i: CallInfo) (this
         |> Some
     | "get_Item", Some ar, [ idx ] -> getExpr r t ar idx |> Some
     | "set_Item", Some ar, [ idx; value ] -> setExpr r ar idx value |> Some
+    | "CopyTo", Some ar, [ target ] ->
+        let count = getFieldWith r t ar "length"
+        copyToArray com r t i [ ar; makeIntConst 0; target; makeIntConst 0; count ]
+    | "CopyTo", Some ar, [ target; targetIndex ] ->
+        let count = getFieldWith r t ar "length"
+        copyToArray com r t i [ ar; makeIntConst 0; target; targetIndex; count ]
+    | "CopyTo", Some ar, [ _sourceIndex; _target; _targetIndex; _count ] -> copyToArray com r t i (ar :: args)
     | "Add", Some ar, [ arg ] ->
         "void ($0)"
         |> emitExpr r t [ Helper.InstanceCall(ar, "push", t, [ arg ]) ]
@@ -1942,10 +1953,6 @@ let tuples (com: ICompiler) (ctx: Context) r (t: Type) (i: CallInfo) (thisArg: E
     | "ToTuple", _ -> changeKind false args
     | _ -> None
 
-let copyToArray (com: ICompiler) r t (i: CallInfo) args =
-    Helper.LibCall(com, "Util", "copyToArray", t, args, i.SignatureArgTypes, genArgs = i.GenericArgs, ?loc = r)
-    |> Some
-
 let arrays (com: ICompiler) (ctx: Context) r (t: Type) (i: CallInfo) (thisArg: Expr option) (args: Expr list) =
     match i.CompiledName, thisArg, args with
     | "get_Length", Some arg, _ -> getFieldWith r t arg "length" |> Some
@@ -2649,6 +2656,11 @@ let dictionaries (com: ICompiler) (ctx: Context) r t (i: CallInfo) (thisArg: Exp
             makeComparerFromEqualityComparer eqComp
             |> makeDictionaryWithComparer com r t arg
             |> Some
+        | [ IEnumerable ], [ arg ] -> makeDictionary com ctx r t arg |> Some
+        | [ IEnumerable; IEqualityComparer ], [ arg; eqComp ] ->
+            makeComparerFromEqualityComparer eqComp
+            |> makeDictionaryWithComparer com r t arg
+            |> Some
         | [ IEqualityComparer ], [ eqComp ]
         | [ Number _; IEqualityComparer ], [ _; eqComp ] ->
             makeComparerFromEqualityComparer eqComp
@@ -2680,6 +2692,13 @@ let dictionaries (com: ICompiler) (ctx: Context) r t (i: CallInfo) (thisArg: Exp
       Some c -> Helper.InstanceCall(c, methName, t, args, i.SignatureArgTypes, ?loc = r) |> Some
     | _ -> None
 
+let collections (com: ICompiler) (ctx: Context) r (t: Type) (i: CallInfo) (thisArg: Expr option) (args: Expr list) =
+    match i.CompiledName, thisArg with
+    | ("get_Count" | "get_IsReadOnly" | "Add" | "Remove" | "Clear" | "Contains" | "CopyTo") as meth, Some ar ->
+        let meth = Naming.removeGetSetPrefix meth |> Naming.lowerFirst
+        Helper.LibCall(com, "CollectionUtil", meth, t, ar :: args, ?loc = r) |> Some
+    | _ -> None
+
 let conditionalWeakTable (com: ICompiler) (ctx: Context) r t (i: CallInfo) (thisArg: Expr option) (args: Expr list) =
     match i.CompiledName, thisArg with
     | ".ctor", _ ->
@@ -3975,8 +3994,8 @@ let private replacedModules =
             Types.resizeArray, resizeArrays
             "System.Collections.Generic.IList`1", resizeArrays
             "System.Collections.IList", resizeArrays
-            Types.icollectionGeneric, resizeArrays
-            Types.icollection, resizeArrays
+            Types.icollectionGeneric, collections
+            Types.icollection, collections
             "System.Collections.Generic.CollectionExtensions", collectionExtensions
             "System.ReadOnlySpan`1", readOnlySpans
             Types.hashset, hashSets

src/fable-library-ts/CollectionUtil.ts

@@ -0,0 +1,134 @@
+import { equals, isArrayLike } from "./Util.js";
+
+export function count<T>(col: Iterable<T>): number {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.get_Count"] === "function") {
+    return (col as any)["System.Collections.Generic.ICollection`1.get_Count"](); // collection
+  } else {
+    if (isArrayLike(col)) {
+      return col.length; // resize array
+    } else {
+      if (typeof (col as any).size === "number") {
+        return (col as any).size; // map, set
+      } else {
+        let count = 0;
+        for (const _ of col) {
+          count++;
+        }
+        return count;
+      }
+    }
+  }
+}
+
+export function isReadOnly<T>(col: Iterable<T>): boolean {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.get_IsReadOnly"] === "function") {
+    return (col as any)["System.Collections.Generic.ICollection`1.get_IsReadOnly"](); // collection
+  } else {
+    return false;
+  }
+}
+
+export function copyTo<T>(col: Iterable<T>, array: T[], arrayIndex: number) {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.CopyToZ3B4C077E"] === "function") {
+    (col as any)["System.Collections.Generic.ICollection`1.CopyToZ3B4C077E"](array, arrayIndex); // collection
+  } else {
+    let i = arrayIndex;
+    for (const v of col) {
+      array[i] = v;
+      i++;
+    }
+  }
+}
+
+export function contains<T>(col: Iterable<T>, item: T): boolean {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.Contains2B595"] === "function") {
+    return (col as any)["System.Collections.Generic.ICollection`1.Contains2B595"](item); // collection
+  } else {
+    if (isArrayLike(col)) {
+      let i = col.findIndex(x => equals(x, item)); // resize array
+      return i >= 0;
+    } else {
+      if (typeof (col as any).has === "function") {
+        if (typeof (col as any).set === "function" && isArrayLike(item)) {
+          return (col as any).has(item[0]) && equals((col as any).get(item[0]), item[1]); // map
+        } else {
+          return (col as any).has(item); // set
+        }
+      } else {
+        return false; // unknown collection
+      }
+    }
+  }
+}
+
+export function add<T>(col: Iterable<T>, item: T): void {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.Add2B595"] === "function") {
+    return (col as any)["System.Collections.Generic.ICollection`1.Add2B595"](item); // collection
+  } else {
+    if (isArrayLike(col)) {
+      col.push(item); // resize array
+    } else {
+      if (typeof (col as any).add === "function") {
+        return (col as any).add(item); // set
+      } else {
+        if (typeof (col as any).has === "function"
+          && typeof (col as any).set === "function"
+          && isArrayLike(item)) {
+          if ((col as any).has(item[0]) === false) {
+            (col as any).set(item[0], item[1]); // map
+          } else {
+            throw new Error("An item with the same key has already been added. Key: " + item[0]);
+          }
+        } else {
+          // unknown collection
+        }
+      }
+    }
+  }
+}
+
+export function remove<T>(col: Iterable<T>, item: T): boolean {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.Remove2B595"] === "function") {
+    return (col as any)["System.Collections.Generic.ICollection`1.Remove2B595"](item); // collection
+  } else {
+    if (isArrayLike(col)) {
+      let i = col.findIndex(x => equals(x, item));
+      if (i >= 0) {
+        col.splice(i, 1); // resize array
+        return true;
+      } else {
+        return false;
+      }
+    } else {
+      if (typeof (col as any).delete === "function") {
+        if (typeof (col as any).set === "function" && isArrayLike(item)) {
+          if ((col as any).has(item[0]) && equals((col as any).get(item[0]), item[1])) {
+            return (col as any).delete(item[0]); // map
+          } else {
+            return false;
+          }
+        } else {
+          return (col as any).delete(item); // set
+        }
+      } else {
+        return false; // unknown collection
+      }
+    }
+  }
+}
+
+export function clear<T>(col: Iterable<T>): void {
+  if (typeof (col as any)["System.Collections.Generic.ICollection`1.Clear"] === "function") {
+    return (col as any)["System.Collections.Generic.ICollection`1.Clear"](); // collection
+  } else {
+    if (isArrayLike(col)) {
+      col.splice(0); // resize array
+    } else {
+      if (typeof (col as any).clear === "function") {
+        (col as any).clear(); // map, set
+      } else {
+        // unknown collection
+      }
+    }
+  }
+}

tests/Dart/src/ArrayTests.fs

@@ -1,10 +1,9 @@
 module Fable.Tests.Dart.Array
 
-open System
 open Util
 
 type ParamArrayTest =
-    static member Add([<ParamArray>] xs: int[]) = Array.sum xs
+    static member Add([<System.ParamArray>] xs: int[]) = Array.sum xs
 
 let add (xs: int[]) = ParamArrayTest.Add(xs)
 
@@ -312,7 +311,7 @@ let tests () =
 // TODO: Char.IsLetter
     // testCase "Array.filter with chars works" <| fun () ->
     //     let xs = [|'a'; '2'; 'b'; 'c'|]
-    //     let ys = xs |> Array.filter Char.IsLetter
+    //     let ys = xs |> Array.filter System.Char.IsLetter
     //     ys.Length |> equal 3
 
     testCase "Array.find works" <| fun () ->
@@ -960,16 +959,16 @@ let tests () =
         ys :? System.Array |> equal true
         zs :? System.Array |> equal false
 
-    testCase "Array.Copy works with numeric arrays" <| fun () ->
+    testCase "System.Array.Copy works with numeric arrays" <| fun () ->
         let source = [| 99 |]
         let destination = [| 1; 2; 3 |]
-        Array.Copy(source, 0, destination, 0, 1)
+        System.Array.Copy(source, 0, destination, 0, 1)
         equal [| 99; 2; 3 |] destination
 
-    testCase "Array.Copy works with non-numeric arrays" <| fun () ->
+    testCase "System.Array.Copy works with non-numeric arrays" <| fun () ->
         let source = [| "xy"; "xx"; "xyz" |]
         let destination = [| "a"; "b"; "c" |]
-        Array.Copy(source, 1, destination, 1, 2)
+        System.Array.Copy(source, 1, destination, 1, 2)
         equal [| "a"; "xx"; "xyz" |] destination
 
     testCase "Array.splitInto works" <| fun () ->
@@ -1102,3 +1101,30 @@ let tests () =
         throwsAnyError (fun () -> Array.removeManyAt 0 2 [||] |> ignore)
         throwsAnyError (fun () -> Array.removeManyAt -1 2 [|1|] |> ignore)
         throwsAnyError (fun () -> Array.removeManyAt 2 2 [|1|] |> ignore)
+
+    // testCase "Array.compareWith works" <| fun () -> // See #2961
+    //     let a = [|1;3|]
+    //     let b = [|1;2;3|]
+    //     // compares lengths first, then elements
+    //     let c1 = a < b
+    //     let c2 = compare a b
+    //     // should compare elements first, then lengths
+    //     let c3 = Array.compareWith compare a b
+    //     equal c1 true
+    //     equal c2 -1
+    //     equal c3 1
+
+    // testCase "System.Array.Resize works" <| fun () ->
+    //     let mutable xs = [|1; 2; 3; 4; 5|]
+    //     System.Array.Resize(&xs, 3)
+    //     xs |> equal [|1; 2; 3|]
+    //     System.Array.Resize(&xs, 7)
+    //     xs |> equal [|1; 2; 3; 0; 0; 0; 0|]
+    //     System.Array.Resize(&xs, 0)
+    //     xs |> equal [||]
+    //     xs <- null
+    //     System.Array.Resize(&xs, 3)
+    //     xs |> equal [|0; 0; 0|]
+    //     xs <- null
+    //     System.Array.Resize(&xs, 0)
+    //     xs |> equal [||]