Use Match for agent service dispatch

ts/EFFECT_NATIVE_REWRITE_AUDIT.md

@@ -481,6 +481,24 @@ Notes:
   - `bun run --cwd ts/packages/flow test`
   - `cd ts && bun run check:tsgo`
 
+### 2026-06-04: Agent Service Match Slice
+
+- Status: migrated and package-verified.
+- Completed:
+  - `ts/packages/flow/src/agent/react/service.ts` no longer uses native
+    `switch` for configured tool construction, live tool wiring, or ReAct
+    continuation parsing.
+  - Configured tool construction now uses `Effect.fn` plus `effect/Match` and
+    preserves unknown-tool logging/fallback behavior.
+  - The ReAct parser is exported for focused tests and uses an exhaustive
+    `Match` over continuation sections.
+  - Agent service tests cover configured-tool loading, unknown configured-tool
+    fallback, default descriptions, MCP tool args, continuation parsing, and
+    final-answer parsing.
+- Verification:
+  - `bun run --cwd ts/packages/flow test -- src/__tests__/agent-service.test.ts`
+  - `cd ts && bun run check:tsgo`
+
 ### 2026-06-02: RAG And Agent Requestor Bridge Slice
 
 - Status: migrated, root-verified, committed, and pushed.

ts/packages/flow/src/__tests__/agent-service.test.ts

@@ -0,0 +1,109 @@
+import { describe, expect, it } from "@effect/vitest";
+import { Effect } from "effect";
+import { makeAgentRuntime, parseReActResponse } from "../agent/react/service.js";
+
+const toolEntry = (entry: Record<string, unknown>): string =>
+  JSON.stringify(entry);
+
+describe("AgentService helpers", () => {
+  it.effect(
+    "loads configured tools through the Match-backed builder",
+    Effect.fnUntraced(function* () {
+      const runtime = yield* makeAgentRuntime;
+
+      yield* runtime.configureTools({
+        tool: {
+          knowledge: toolEntry({
+            type: "knowledge-query",
+            name: "Knowledge",
+          }),
+          document: toolEntry({
+            type: "document-query",
+            name: "Document",
+            description: "Find document context.",
+          }),
+          triples: toolEntry({
+            type: "triples-query",
+            name: "Triples",
+          }),
+          mcp: toolEntry({
+            type: "mcp-tool",
+            name: "Lookup",
+            description: "Call an external lookup tool.",
+            arguments: [
+              {
+                name: "query",
+                type: "string",
+                description: "Lookup query.",
+              },
+            ],
+          }),
+          unknown: toolEntry({
+            type: "unknown-tool",
+            name: "Ignored",
+          }),
+        },
+      }, 1);
+
+      const tools = yield* runtime.getConfiguredTools;
+
+      expect(tools?.map((tool) => tool.name)).toEqual([
+        "Knowledge",
+        "Document",
+        "Triples",
+        "Lookup",
+      ]);
+      expect(tools?.map((tool) => tool.config?.type)).toEqual([
+        "knowledge-query",
+        "document-query",
+        "triples-query",
+        "mcp-tool",
+      ]);
+      expect(tools?.[0]?.description).toBe(
+        "Query the knowledge graph for information about entities and their relationships.",
+      );
+      expect(tools?.[1]?.description).toBe("Find document context.");
+      expect(tools?.[3]?.args).toEqual([
+        {
+          name: "query",
+          type: "string",
+          description: "Lookup query.",
+        },
+      ]);
+    }),
+  );
+
+  it("parses ReAct continuation sections through the Match-backed parser", () => {
+    const parsed = parseReActResponse([
+      "Thought: first idea",
+      "continued idea",
+      "Action: Search",
+      "extra action words",
+      "Action Input: {\"question\":\"hello\"}",
+      "continued input",
+    ].join("\n"));
+
+    expect(parsed).toEqual({
+      thought: "first idea\ncontinued idea",
+      action: "Search extra action words",
+      actionInput: "{\"question\":\"hello\"}\ncontinued input",
+      finalAnswer: "",
+    });
+  });
+
+  it("parses final answers and ignores later text", () => {
+    const parsed = parseReActResponse([
+      "Thought: done",
+      "Final Answer: answer one",
+      "answer two",
+      "Action: ignored",
+    ].join("\n"));
+
+    expect(parsed).toEqual({
+      thought: "done",
+      action: "",
+      actionInput: "",
+      finalAnswer: "answer one\nanswer two\nAction: ignored",
+    });
+  });
+});

ts/packages/flow/src/agent/react/service.ts

@@ -46,7 +46,7 @@ import {
   type MessagingDeliveryError,
   type Spec,
 } from "@trustgraph/base";
-import {Context, Effect, Layer, ManagedRuntime, Ref} from "effect";
+import {Context, Effect, Layer, ManagedRuntime, Match, Ref} from "effect";
 import * as O from "effect/Option";
 import * as Predicate from "effect/Predicate";
 import * as S from "effect/Schema";
@@ -133,83 +133,87 @@ export class AgentRuntime extends Context.Service<AgentRuntime, AgentRuntimeServ
   "@trustgraph/flow/agent/react/service/AgentRuntime",
 ) {}
 
-const buildConfiguredTool = (
+const buildConfiguredTool = Effect.fn("AgentService.buildConfiguredTool")(function* (
   toolId: string,
   data: ToolConfigEntry,
-): Effect.Effect<AgentTool | null> =>
-  Effect.gen(function* () {
-    const implType = data.type ?? "";
-    const name = data.name ?? "";
-    const description = data.description ?? "";
-    const config: Record<string, unknown> = { ...data };
+) {
+  const implType = data.type ?? "";
+  const name = data.name ?? "";
+  const description = data.description ?? "";
+  const config: Record<string, unknown> = { ...data };
 
-    if (name.length === 0) {
-      yield* Effect.logWarning(`[AgentService] Skipping tool with no name: ${toolId}`);
-      return null;
-    }
+  if (name.length === 0) {
+    yield* Effect.logWarning(`[AgentService] Skipping tool with no name: ${toolId}`);
+    return null;
+  }
 
-    switch (implType) {
-      case "knowledge-query":
-        return {
-          name,
-          description:
-            description.length > 0
-              ? description
-              : "Query the knowledge graph for information about entities and their relationships.",
-          args: [{ name: "question", type: "string", description: "The question to ask" }],
-          config,
-          execute: () => Promise.resolve(""),
-        };
+  return yield* Match.value(implType).pipe(
+    Match.when("knowledge-query", () =>
+      Effect.succeed({
+        name,
+        description:
+          description.length > 0
+            ? description
+            : "Query the knowledge graph for information about entities and their relationships.",
+        args: [{ name: "question", type: "string", description: "The question to ask" }],
+        config,
+        execute: () => Promise.resolve(""),
+      })
+    ),
 
-      case "document-query":
-        return {
-          name,
-          description:
-            description.length > 0
-              ? description
-              : "Search documents for relevant information.",
-          args: [{ name: "question", type: "string", description: "The question to search for" }],
-          config,
-          execute: () => Promise.resolve(""),
-        };
+    Match.when("document-query", () =>
+      Effect.succeed({
+        name,
+        description:
+          description.length > 0
+            ? description
+            : "Search documents for relevant information.",
+        args: [{ name: "question", type: "string", description: "The question to search for" }],
+        config,
+        execute: () => Promise.resolve(""),
+      })
+    ),
 
-      case "triples-query":
-        return {
-          name,
-          description:
-            description.length > 0
-              ? description
-              : "Query for specific triples in the knowledge graph.",
-          args: [
-            { name: "subject", type: "string", description: "Subject entity (optional)" },
-            { name: "predicate", type: "string", description: "Predicate/relationship (optional)" },
-            { name: "object", type: "string", description: "Object entity (optional)" },
-          ],
-          config,
-          execute: () => Promise.resolve(""),
-        };
+    Match.when("triples-query", () =>
+      Effect.succeed({
+        name,
+        description:
+          description.length > 0
+            ? description
+            : "Query for specific triples in the knowledge graph.",
+        args: [
+          { name: "subject", type: "string", description: "Subject entity (optional)" },
+          { name: "predicate", type: "string", description: "Predicate/relationship (optional)" },
+          { name: "object", type: "string", description: "Object entity (optional)" },
+        ],
+        config,
+        execute: () => Promise.resolve(""),
+      })
+    ),
 
-      case "mcp-tool": {
-        const args: ToolArg[] = (data.arguments ?? []).map((arg) => ({
-          name: arg.name ?? "",
-          type: arg.type ?? "string",
-          description: arg.description ?? "",
-        }));
+    Match.when("mcp-tool", () => {
+      const args: ToolArg[] = (data.arguments ?? []).map((arg) => ({
+        name: arg.name ?? "",
+        type: arg.type ?? "string",
+        description: arg.description ?? "",
+      }));
 
-        return {
-          name,
-          description,
-          args,
-          config,
-          execute: () => Promise.resolve(""),
-        };
-      }
+      return Effect.succeed({
+        name,
+        description,
+        args,
+        config,
+        execute: () => Promise.resolve(""),
+      });
+    }),
 
-      default:
-        yield* Effect.logWarning(`[AgentService] Unknown tool type "${implType}" for ${name}`);
-        return null;
-    }
-  });
+    Match.orElse(() =>
+      Effect.logWarning(`[AgentService] Unknown tool type "${implType}" for ${name}`).pipe(
+        Effect.as(null),
+      )
+    ),
+  );
+});
 
 const loadConfiguredTools = Effect.fn("AgentRuntime.loadConfiguredTools")(function* (
   config: Record<string, unknown>,
@@ -284,30 +288,30 @@ const wireTools = Effect.fn("AgentService.wireTools")(function* (
     const rawImplType = tool.config?.type;
     const implType = Predicate.isString(rawImplType) ? rawImplType : undefined;
 
-    switch (implType) {
-      case "knowledge-query": {
+    return Match.value(implType).pipe(
+      Match.when("knowledge-query", () => {
         const live = createKnowledgeQueryTool(
           graphRag,
           collection,
           onExplain,
         );
         return { ...tool, execute: live.execute };
-      }
-      case "document-query": {
+      }),
+      Match.when("document-query", () => {
         const live = createDocumentQueryTool(
           docRag,
           collection,
         );
         return { ...tool, execute: live.execute };
-      }
-      case "triples-query": {
+      }),
+      Match.when("triples-query", () => {
         const live = createTriplesQueryTool(
           triples,
           collection,
         );
         return { ...tool, execute: live.execute };
-      }
-      case "mcp-tool": {
+      }),
+      Match.when("mcp-tool", () => {
         const live = createMcpTool(
           mcpTool,
           tool.name,
@@ -315,10 +319,9 @@ const wireTools = Effect.fn("AgentService.wireTools")(function* (
           tool.args,
         );
         return { ...tool, execute: live.execute };
-      }
-      default:
-        return tool;
-    }
+      }),
+      Match.orElse(() => tool),
+    );
   });
 });
 
@@ -534,7 +537,7 @@ export const AgentService = makeAgentService;
  * For the MVP this avoids the complexity of the streaming parser --
  * we parse the complete response at once.
  */
-function parseReActResponse(text: string): {
+export function parseReActResponse(text: string): {
   thought: string;
   action: string;
   actionInput: string;
@@ -582,18 +585,19 @@ function parseReActResponse(text: string): {
       currentSection = null;
     } else if (trimmed.length > 0 && currentSection !== null) {
       // Continuation line for current section
-      switch (currentSection) {
-        case "thought":
+      Match.value(currentSection).pipe(
+        Match.when("thought", () => {
           thought += "\n" + trimmed;
-          break;
-        case "action":
+        }),
+        Match.when("action", () => {
           // Action should be a single line (tool name), but handle multi-line
           action += " " + trimmed;
-          break;
-        case "action_input":
+        }),
+        Match.when("action_input", () => {
           actionInput += "\n" + trimmed;
-          break;
-      }
+        }),
+        Match.exhaustive,
+      );
     }
   }