fix(symbolConverter): do not register colliding outcome slugs

src/utils/_symbolConverter.ts

@@ -212,19 +212,32 @@ export class SymbolConverter {
     // Fallback outcomes are not tradable on their own and have no public slug
     const fallbackOutcomes = new Set(outcomeMetaData.questions.map((question) => question.fallbackOutcome));
 
+    // Markets deployed from a template share their question, outcome and side names, so several
+    // tradable sides can slugify to the same string. Such a slug is unregistered below, so a lookup
+    // returns `undefined` instead of whichever market was loaded last.
+    const seenSlugs = new Set<string>();
+    const ambiguousSlugs = new Set<string>();
+
     outcomeMetaData.outcomes.forEach((outcome) => {
       if (fallbackOutcomes.has(outcome.outcome)) return;
       const question = questionByOutcome.get(outcome.outcome);
 
       outcome.sideSpecs.forEach((sideSpec, sideIdx) => {
         const slug = this._outcomeSlug(outcome, sideSpec.name, question);
         if (!slug) return;
+        if (seenSlugs.has(slug)) ambiguousSlugs.add(slug);
+        seenSlugs.add(slug);
 
         this._nameToAssetId.set(slug, 100000000 + 10 * outcome.outcome + sideIdx);
         // Outcome markets are absent from szDecimals metadata; they are all 5
         this._nameToSzDecimals.set(slug, 5);
       });
     });
+
+    ambiguousSlugs.forEach((slug) => {
+      this._nameToAssetId.delete(slug);
+      this._nameToSzDecimals.delete(slug);
+    });
   }
 
   /**

tests/utils/symbolConverter.test.ts

@@ -148,6 +148,53 @@ const OUTCOME_META: OutcomeMetaResponse = {
   ],
 };
 
+/**
+ * An `outcomeMeta` response modeled on templated mainnet markets. Their display names are template
+ * ids rather than the market's own name, so distinct markets slugify to the same string.
+ */
+const TEMPLATED_OUTCOME_META: OutcomeMetaResponse = {
+  outcomes: [
+    {
+      outcome: 300,
+      name: "template:binaryPrice",
+      description: "perp:BTC|threshold:61720|time:20260608-0600",
+      sideSpecs: [{ name: "template:Yes" }, { name: "template:No" }],
+      quoteToken: "USDC",
+    },
+    {
+      outcome: 301,
+      name: "template:binaryPrice",
+      description: "perp:ETH|threshold:2400|time:20260608-0600",
+      sideSpecs: [{ name: "template:Yes" }, { name: "template:No" }],
+      quoteToken: "USDC",
+    },
+    {
+      outcome: 302,
+      name: "Uniquely Named Market",
+      description: "",
+      sideSpecs: [{ name: "Yes" }, { name: "No" }],
+      quoteToken: "USDC",
+    },
+    {
+      outcome: 303,
+      name: "Fallback",
+      description: "",
+      sideSpecs: [{ name: "Yes" }, { name: "No" }],
+      quoteToken: "USDC",
+    },
+  ],
+  questions: [
+    {
+      question: 40,
+      name: "Weekly Price Markets",
+      description: "",
+      fallbackOutcome: 303,
+      namedOutcomes: [302],
+      settledNamedOutcomes: [],
+    },
+  ],
+};
+
 // ============================================================
 // Tests
 // ============================================================
@@ -297,3 +344,21 @@ Deno.test("SymbolConverter outcome markets", async (t) => {
     assertEquals(converter.getSzDecimals("2026-world-cup-champion-argentina-yes"), 5);
   });
 });
+
+Deno.test("SymbolConverter templated outcome markets", async (t) => {
+  const converter = await SymbolConverter.create({ transport: createOutcomeTransport(TEMPLATED_OUTCOME_META) });
+
+  await t.step("ambiguous slugs are not registered", () => {
+    // Outcomes 300 and 301 are different markets that slugify identically, so neither may win the
+    // lookup: before this was handled, the id of whichever loaded last was returned for both.
+    assertEquals(converter.getAssetId("templatebinaryprice-templateyes"), undefined);
+    assertEquals(converter.getAssetId("templatebinaryprice-templateno"), undefined);
+    assertEquals(converter.getSzDecimals("templatebinaryprice-templateyes"), undefined);
+  });
+
+  await t.step("unique slugs are still registered", () => {
+    assertEquals(converter.getAssetId("weekly-price-markets-uniquely-named-market-yes"), 100003020);
+    assertEquals(converter.getAssetId("weekly-price-markets-uniquely-named-market-no"), 100003021);
+    assertEquals(typeof converter.getSzDecimals("weekly-price-markets-uniquely-named-market-yes"), "number");
+  });
+});