fix(core): throw InsufficientInputs for token targets no input can reach

.changeset/tidy-selection-fails.md

@@ -0,0 +1,5 @@
+---
+"@fleet-sdk/core": patch
+---
+
+fix(core): throw InsufficientInputs when a token target cannot be reached because no selected input holds the token, instead of crashing with "Empty array." or a TypeError on empty selections

packages/core/src/builder/selector/boxSelector.spec.ts

@@ -243,6 +243,30 @@ describe("Validations", () => {
     }).toThrow(InsufficientInputs);
   });
 
+  it("Should fail if tokens target is unreached and no input holds the token", () => {
+    const tokenId = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+    const selector = new BoxSelector(regularBoxes);
+
+    let error: unknown;
+    try {
+      selector.select({ tokens: [{ tokenId, amount: 100n }] });
+    } catch (e) {
+      error = e;
+    }
+
+    expect(error).toBeInstanceOf(InsufficientInputs);
+    expect((error as InsufficientInputs).unreached.tokens).toEqual([{ tokenId, amount: 100n }]);
+  });
+
+  it("Should fail if tokens target is unreached and there are no inputs at all", () => {
+    const tokenId = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+    const selector = new BoxSelector([]);
+
+    expect(() => {
+      selector.select({ tokens: [{ tokenId, amount: 100n }] });
+    }).toThrow(InsufficientInputs);
+  });
+
   it("Should fail if any target is unreached", () => {
     const tokenId = "0cd8c9f416e5b1ca9f986a7f10a84191dfb85941619e49e53c0dc30ebf83324b";
     const selector = new BoxSelector(regularBoxes);

packages/core/src/builder/selector/boxSelector.ts

@@ -68,7 +68,7 @@ export class BoxSelector<T extends Box<bigint>> {
     let inclusion = this._ensureInclusionBoxIds;
 
     // if the target has a token that is being minted, then the first input should be included
-    if (target.tokens?.some((x) => x.tokenId === unselected[0].boxId)) {
+    if (some(unselected) && target.tokens?.some((x) => x.tokenId === unselected[0].boxId)) {
       inclusion = new Set(this._ensureInclusionBoxIds).add(unselected[0].boxId);
     }
 
@@ -139,7 +139,7 @@ export class BoxSelector<T extends Box<bigint>> {
     for (const tokenTarget of target.tokens) {
       const totalSelected = utxoSum(inputs, tokenTarget.tokenId);
       if (tokenTarget.amount && tokenTarget.amount > totalSelected) {
-        if (tokenTarget.tokenId === first(inputs).boxId) {
+        if (some(inputs) && tokenTarget.tokenId === first(inputs).boxId) {
           // if the token is the same as the first input, then it is being minted
           continue;
         }