fix(guided-flow): route dispatchWorkflow through dynamic routing pipeline (#3153)

Closes #2958

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/resources/extensions/gsd/guided-flow.ts

@@ -38,7 +38,7 @@ import { showConfirm } from "../shared/tui.js";
 import { debugLog } from "./debug-logger.js";
 import { findMilestoneIds, nextMilestoneId, reserveMilestoneId, getReservedMilestoneIds, clearReservedMilestoneIds } from "./milestone-ids.js";
 import { parkMilestone, discardMilestone } from "./milestone-actions.js";
-import { resolveModelWithFallbacksForUnit } from "./preferences-models.js";
+import { selectAndApplyModel } from "./auto-model-selection.js";
 
 // ─── Re-exports (preserve public API for existing importers) ────────────────
 export {
@@ -224,24 +224,20 @@ async function dispatchWorkflow(
   ctx?: ExtensionContext,
   unitType?: string,
 ): Promise<void> {
-  // Apply model preference for this unit type (if configured)
+  // Route through the dynamic routing pipeline (complexity classification,
+  // tier downgrade, fallback chains) — same path as auto-mode dispatches (#2958).
   if (ctx && unitType) {
-    const modelConfig = resolveModelWithFallbacksForUnit(unitType);
-    if (modelConfig) {
-      const availableModels = ctx.modelRegistry.getAvailable();
-      const modelsToTry = [modelConfig.primary, ...modelConfig.fallbacks];
-
-      for (const modelId of modelsToTry) {
-        // Resolve model from available models (same logic as auto-model-selection)
-        const model = resolveAvailableModel(modelId, availableModels, ctx.model?.provider);
-        if (!model) continue;
-
-        const ok = await pi.setModel(model, { persist: false });
-        if (ok) {
-          debugLog("guided-flow-model-applied", { unitType, model: `${model.provider}/${model.id}` });
-          break;
-        }
-      }
+    const prefs = loadEffectiveGSDPreferences()?.preferences;
+    const result = await selectAndApplyModel(
+      ctx, pi, unitType, /* unitId */ "", /* basePath */ process.cwd(),
+      prefs, /* verbose */ false, /* autoModeStartModel */ null,
+    );
+    if (result.appliedModel) {
+      debugLog("guided-flow-model-applied", {
+        unitType,
+        model: `${result.appliedModel.provider}/${result.appliedModel.id}`,
+        routing: result.routing,
+      });
     }
   }
 

src/resources/extensions/gsd/tests/guided-flow-dynamic-routing.test.ts

@@ -0,0 +1,135 @@
+/**
+ * Guided-flow dynamic routing — regression test for #2958.
+ *
+ * Verifies that dispatchWorkflow() routes through the dynamic routing pipeline
+ * (selectAndApplyModel from auto-model-selection.ts) instead of bypassing it
+ * with a direct call to resolveModelWithFallbacksForUnit.
+ *
+ * Copyright (c) 2026 Jeremy McSpadden <jeremy@fluxlabs.net>
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { join, dirname } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const gsdDir = join(__dirname, "..");
+
+function readSrc(file: string): string {
+  return readFileSync(join(gsdDir, file), "utf-8");
+}
+
+const guidedFlowSrc = readSrc("guided-flow.ts");
+
+// ═══════════════════════════════════════════════════════════════════════════
+// #2958: dispatchWorkflow must route through dynamic routing pipeline
+// ═══════════════════════════════════════════════════════════════════════════
+
+test("#2958: guided-flow imports selectAndApplyModel from auto-model-selection", () => {
+  assert.ok(
+    guidedFlowSrc.includes("selectAndApplyModel"),
+    "guided-flow.ts must import and use selectAndApplyModel from auto-model-selection.ts",
+  );
+});
+
+test("#2958: dispatchWorkflow does not call resolveModelWithFallbacksForUnit directly", () => {
+  // Extract the dispatchWorkflow function body
+  const fnStart = guidedFlowSrc.indexOf("async function dispatchWorkflow(");
+  assert.ok(fnStart !== -1, "dispatchWorkflow function not found");
+
+  // Find the function body by tracking brace depth
+  const openBrace = guidedFlowSrc.indexOf("{", fnStart);
+  let depth = 1;
+  let pos = openBrace + 1;
+  while (depth > 0 && pos < guidedFlowSrc.length) {
+    if (guidedFlowSrc[pos] === "{") depth++;
+    else if (guidedFlowSrc[pos] === "}") depth--;
+    pos++;
+  }
+  const fnBody = guidedFlowSrc.slice(openBrace, pos);
+
+  assert.ok(
+    !fnBody.includes("resolveModelWithFallbacksForUnit"),
+    "dispatchWorkflow must NOT call resolveModelWithFallbacksForUnit directly — " +
+    "it must route through selectAndApplyModel for dynamic routing support (#2958)",
+  );
+});
+
+test("#2958: dispatchWorkflow calls selectAndApplyModel for model selection", () => {
+  // Extract the dispatchWorkflow function body
+  const fnStart = guidedFlowSrc.indexOf("async function dispatchWorkflow(");
+  assert.ok(fnStart !== -1, "dispatchWorkflow function not found");
+
+  const openBrace = guidedFlowSrc.indexOf("{", fnStart);
+  let depth = 1;
+  let pos = openBrace + 1;
+  while (depth > 0 && pos < guidedFlowSrc.length) {
+    if (guidedFlowSrc[pos] === "{") depth++;
+    else if (guidedFlowSrc[pos] === "}") depth--;
+    pos++;
+  }
+  const fnBody = guidedFlowSrc.slice(openBrace, pos);
+
+  assert.ok(
+    fnBody.includes("selectAndApplyModel"),
+    "dispatchWorkflow must call selectAndApplyModel to route through the dynamic routing pipeline (#2958)",
+  );
+});
+
+test("#2958: dispatchWorkflow does not use resolveAvailableModel inline", () => {
+  const fnStart = guidedFlowSrc.indexOf("async function dispatchWorkflow(");
+  assert.ok(fnStart !== -1, "dispatchWorkflow function not found");
+
+  const openBrace = guidedFlowSrc.indexOf("{", fnStart);
+  let depth = 1;
+  let pos = openBrace + 1;
+  while (depth > 0 && pos < guidedFlowSrc.length) {
+    if (guidedFlowSrc[pos] === "{") depth++;
+    else if (guidedFlowSrc[pos] === "}") depth--;
+    pos++;
+  }
+  const fnBody = guidedFlowSrc.slice(openBrace, pos);
+
+  assert.ok(
+    !fnBody.includes("resolveAvailableModel"),
+    "dispatchWorkflow must NOT use resolveAvailableModel inline — " +
+    "model resolution is handled by selectAndApplyModel (#2958)",
+  );
+});
+
+test("#2958: guided-flow does not import resolveModelWithFallbacksForUnit", () => {
+  // The import should be removed since dispatchWorkflow was the only consumer
+  // Check if resolveModelWithFallbacksForUnit is still used elsewhere in the file
+  const fnStart = guidedFlowSrc.indexOf("async function dispatchWorkflow(");
+  const beforeDispatch = guidedFlowSrc.slice(0, fnStart);
+  const afterFnEnd = (() => {
+    const openBrace = guidedFlowSrc.indexOf("{", fnStart);
+    let depth = 1;
+    let p = openBrace + 1;
+    while (depth > 0 && p < guidedFlowSrc.length) {
+      if (guidedFlowSrc[p] === "{") depth++;
+      else if (guidedFlowSrc[p] === "}") depth--;
+      p++;
+    }
+    return guidedFlowSrc.slice(p);
+  })();
+
+  // If resolveModelWithFallbacksForUnit is not used outside dispatchWorkflow,
+  // the import should be removed
+  const usedOutside = beforeDispatch.includes("resolveModelWithFallbacksForUnit(")
+    || afterFnEnd.includes("resolveModelWithFallbacksForUnit(");
+
+  if (!usedOutside) {
+    // Verify the import line was cleaned up
+    const importLines = guidedFlowSrc.split("\n").filter(l =>
+      l.includes("import") && l.includes("resolveModelWithFallbacksForUnit"),
+    );
+    assert.equal(
+      importLines.length,
+      0,
+      "resolveModelWithFallbacksForUnit import should be removed when no longer used outside dispatchWorkflow",
+    );
+  }
+});