fix(5.0): bad unpack() call in SparseArraySpread (#1347)

YoRyan · web-flow · commit a2219728eef6 · 2022-09-17T17:18:18.000+02:00
diff --git a/src/lualib/5.0/SparseArraySpread.ts b/src/lualib/5.0/SparseArraySpread.ts
@@ -1,5 +1,6 @@
 import { __TS__SparseArray } from "./SparseArray";
+import { __TS__Unpack } from "./Unpack";
 
 export function __TS__SparseArraySpread<T>(this: void, sparseArray: __TS__SparseArray<T>): LuaMultiReturn<T[]> {
-    return unpack(sparseArray, 1, sparseArray.sparseLength);
+    return __TS__Unpack(sparseArray, 1, sparseArray.sparseLength);
 }
diff --git a/src/lualib/5.0/Unpack.ts b/src/lualib/5.0/Unpack.ts
@@ -1 +1,16 @@
-export const __TS__Unpack = unpack;
+/** @noSelfInFile */
+
+// We're not interested in emulating all of the behaviors of unpack() from Lua
+// 5.1, just the ones needed by other parts of lualib.
+export function __TS__Unpack<T>(list: T[], i: number, j?: number): LuaMultiReturn<T[]> {
+    if (i === 1 && j === undefined) {
+        return unpack(list);
+    } else {
+        j ??= list.length;
+        const slice: T[] = [];
+        for (let n = i; n <= j; n++) {
+            slice[n - i] = list[n - 1]; // We don't want to add 1 to the index into list.
+        }
+        return $multi(...slice);
+    }
+}
diff --git a/src/lualib/declarations/tstl.d.ts b/src/lualib/declarations/tstl.d.ts
@@ -18,9 +18,6 @@ interface LuaClassInstance extends LuaMetatable<any> {
     constructor: LuaClass;
 }
 
-// Declare unpack for versions that have it instead of table.unpack
-declare const unpack: typeof table.unpack | undefined;
-
 // Declare math atan2 for versions that have it instead of math.atan
 declare namespace math {
     const atan2: typeof atan;
diff --git a/src/lualib/declarations/universal/unpack.d.ts b/src/lualib/declarations/universal/unpack.d.ts
@@ -0,0 +1,4 @@
+/** @noSelfInFile */
+
+// Declare unpack for versions that have it instead of table.unpack
+declare const unpack: typeof table.unpack | undefined;

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,6 @@`
`1`	`1`	`import { __TS__SparseArray } from "./SparseArray";`
	`2`	`+import { __TS__Unpack } from "./Unpack";`
`2`	`3`
`3`	`4`	`export function __TS__SparseArraySpread<T>(this: void, sparseArray: __TS__SparseArray<T>): LuaMultiReturn<T[]> {`
`4`		`- return unpack(sparseArray, 1, sparseArray.sparseLength);`
	`5`	`+ return __TS__Unpack(sparseArray, 1, sparseArray.sparseLength);`
`5`	`6`	`}`
Original file line number	Diff line number	Diff line change
`@@ -18,9 +18,6 @@ interface LuaClassInstance extends LuaMetatable<any> {`
`18`	`18`	`constructor: LuaClass;`
`19`	`19`	`}`
`20`	`20`
`21`		`-// Declare unpack for versions that have it instead of table.unpack`
`22`		`-declare const unpack: typeof table.unpack \| undefined;`
`23`		`-`
`24`	`21`	`// Declare math atan2 for versions that have it instead of math.atan`
`25`	`22`	`declare namespace math {`
`26`	`23`	`const atan2: typeof atan;`