support long else...if blocks?

src/combat.ts

@@ -25,6 +25,7 @@ import {
   overlappingSkillNames,
 } from "./overlappingNames.js";
 import { get, set } from "./property.js";
+import { notNullish } from "./utils.js";
 
 const MACRO_NAME = "Script Autoattack Macro";
 /**
@@ -185,6 +186,14 @@ type Constructor<T> = { new (): T };
 
 export class InvalidMacroError extends Error {}
 
+export type ElseIfComponent = {
+  predicate: PreBALLSPredicate;
+  macro: string | Macro;
+};
+export type ElseTrain =
+  | ElseIfComponent[]
+  | [...ElseIfComponent[], undefined | string | Macro];
+
 /**
  * BALLS macro builder for direct submission to KoL.
  * Create a new macro with `new Macro()` and add steps using the instance methods.
@@ -549,38 +558,62 @@ export class Macro {
    *
    * @param condition The BALLS condition for the if statement.
    * @param ifTrue Continuation if the condition is true.
-   * @param ifFalse Optional else-branch for the macro.
+   * @param elseTrain Spread array of { predicate, macro } elif entries, followed by an final bare string/Macro for the final Else.
    * @returns {Macro} This object itself.
    */
   if_(
     condition: PreBALLSPredicate,
     ifTrue: string | Macro,
-    ifFalse?: string | Macro,
+    ...elseTrain: ElseTrain
+  ): this;
+  /**
+   * Add an "if" statement to this macro, followed by a long chain of "elif"s, followed optionally by an "else"
+   *
+   * @param elseTrain Spread array of { predicate, macro } elif entries, followed by an final bare string/Macro for the final Else.
+   * @returns {Macro} This object itself.
+   */
+  if_(...elseTrain: ElseTrain): this;
+  if_(
+    leadingArg: PreBALLSPredicate | ElseIfComponent,
+    secondArg: typeof leadingArg extends ElseIfComponent
+      ? ElseIfComponent | undefined
+      : string | Macro,
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    ...rest: any[]
   ): this {
-    this.step(`if ${Macro.makeBALLSPredicate(condition)}`).step(ifTrue);
+    if (!(typeof leadingArg === "object" && "predicate" in leadingArg)) {
+      this.step(`if ${Macro.makeBALLSPredicate(leadingArg)}`, secondArg);
+    }
 
-    if (ifFalse) {
-      this.step("else").step(ifFalse);
+    for (const elseEntry of (rest as ElseTrain[number][]).filter(notNullish)) {
+      if (typeof elseEntry === "object" && !(elseEntry instanceof Macro)) {
+        const { predicate, macro } = elseEntry;
+        this.step(`elif ${Macro.makeBALLSPredicate(predicate)}`).step(macro);
+      } else {
+        this.step("else").step(elseEntry);
+      }
     }
 
-    return this.step("endif");
+    this.step("endif");
+
+    return this;
   }
 
   /**
    * Create a new macro with an "if" statement.
    *
    * @param condition The BALLS condition for the if statement.
    * @param ifTrue Continuation if the condition is true.
-   * @param ifFalse Optional else-branch for the macro.
+   * @param elseTrain Spread array of { predicate, macro } elif entries, followed by an final bare string/Macro for the final Else.
    * @returns {Macro} This object itself.
    */
   static if_<T extends Macro>(
     this: Constructor<T>,
     condition: PreBALLSPredicate,
     ifTrue: string | Macro,
-    ifFalse?: string | Macro,
+    ...elseTrain: ElseTrain
   ): T {
-    return new this().if_(condition, ifTrue, ifFalse);
+    return new this().if_(condition, ifTrue, ...elseTrain);
   }
 
   /**