Array.map caused ERROR TS1140: Type argument expected.

[abcfy2]

      const attributes: string[] = metadata
        .get("attributes")!
        .toArray()
        .map((item: JSONValue, idx: number): string => {
          const attrId: string = id + "-" + idx.toString();
          const attribute = item.toObject();
          const attr = new APEAttr(attrId);
          attr.trait_type = attribute.get("trait_type")!.toString();
          attr.value = attribute.get("value")!.toString();
          attr.save();
          return attrId;
        });

Error:

⠋ Compile subgraphERROR TS1140: Type argument expected.

         .map((item: JSONValue, idx: number): string => {
             ^
 in src/mapping.ts(55,13)

✖ Failed to compile subgraph: Failed to compile data source mapping: 1 compile error(s)

Reproduce: https://www.assemblyscript.org/editor.html#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

;; INFO asc module.ts --textFile module.wat --binaryFile module.wasm -O3 --runtime stub
;; ERROR TS1140: Type argument expected.
;; 
;;  arr.map((item: number, idx: number): number => {
;;         ^
;;  in module.ts(2,8)
(module
 ;; FAILURE 1 compile error(s)
)

[SebastianSpeitel]

AssemblyScript doesn't have number. You have to be more specific like u32.

[abcfy2]

Still not working:

const arr: u32[] = [1,2,3,4,5];
arr.map((item: u32, idx: u32): u32 => {
  return item + idx
});

ERROR:

;; INFO asc module.ts --textFile module.wat --binaryFile module.wasm -O3 --runtime stub
;; ERROR TS1140: Type argument expected.
;; 
;;  arr.map((item: u32, idx: u32): u32 => {
;;         ^
;;  in module.ts(2,8)
(module
 ;; FAILURE 1 compile error(s)
)

[abcfy2]

Solved:

const arr: u32[] = [1,2,3,4,5];
arr.map<u32>((item: u32, idx: u32): u32 => {
  return item + idx
});