Slack: add modal private metadata utilities

src/slack/modal-metadata.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, it } from "vitest";
+import {
+  encodeSlackModalPrivateMetadata,
+  parseSlackModalPrivateMetadata,
+} from "./modal-metadata.js";
+
+describe("parseSlackModalPrivateMetadata", () => {
+  it("returns empty object for missing or invalid values", () => {
+    expect(parseSlackModalPrivateMetadata(undefined)).toEqual({});
+    expect(parseSlackModalPrivateMetadata("")).toEqual({});
+    expect(parseSlackModalPrivateMetadata("{bad-json")).toEqual({});
+  });
+
+  it("parses known metadata fields", () => {
+    expect(
+      parseSlackModalPrivateMetadata(
+        JSON.stringify({
+          sessionKey: "agent:main:slack:channel:C1",
+          channelId: "D123",
+          channelType: "im",
+          ignored: "x",
+        }),
+      ),
+    ).toEqual({
+      sessionKey: "agent:main:slack:channel:C1",
+      channelId: "D123",
+      channelType: "im",
+    });
+  });
+});
+
+describe("encodeSlackModalPrivateMetadata", () => {
+  it("encodes only known non-empty fields", () => {
+    expect(
+      JSON.parse(
+        encodeSlackModalPrivateMetadata({
+          sessionKey: "agent:main:slack:channel:C1",
+          channelId: "",
+          channelType: "im",
+        }),
+      ),
+    ).toEqual({
+      sessionKey: "agent:main:slack:channel:C1",
+      channelType: "im",
+    });
+  });
+
+  it("throws when encoded payload exceeds Slack metadata limit", () => {
+    expect(() =>
+      encodeSlackModalPrivateMetadata({
+        sessionKey: `agent:main:${"x".repeat(4000)}`,
+      }),
+    ).toThrow(/cannot exceed 3000 chars/i);
+  });
+});

src/slack/modal-metadata.ts

@@ -0,0 +1,42 @@
+export type SlackModalPrivateMetadata = {
+  sessionKey?: string;
+  channelId?: string;
+  channelType?: string;
+};
+
+const SLACK_PRIVATE_METADATA_MAX = 3000;
+
+function normalizeString(value: unknown) {
+  return typeof value === "string" && value.trim().length > 0 ? value.trim() : undefined;
+}
+
+export function parseSlackModalPrivateMetadata(raw: unknown): SlackModalPrivateMetadata {
+  if (typeof raw !== "string" || raw.trim().length === 0) {
+    return {};
+  }
+  try {
+    const parsed = JSON.parse(raw) as Record<string, unknown>;
+    return {
+      sessionKey: normalizeString(parsed.sessionKey),
+      channelId: normalizeString(parsed.channelId),
+      channelType: normalizeString(parsed.channelType),
+    };
+  } catch {
+    return {};
+  }
+}
+
+export function encodeSlackModalPrivateMetadata(input: SlackModalPrivateMetadata): string {
+  const payload: SlackModalPrivateMetadata = {
+    ...(input.sessionKey ? { sessionKey: input.sessionKey } : {}),
+    ...(input.channelId ? { channelId: input.channelId } : {}),
+    ...(input.channelType ? { channelType: input.channelType } : {}),
+  };
+  const encoded = JSON.stringify(payload);
+  if (encoded.length > SLACK_PRIVATE_METADATA_MAX) {
+    throw new Error(
+      `Slack modal private_metadata cannot exceed ${SLACK_PRIVATE_METADATA_MAX} chars`,
+    );
+  }
+  return encoded;
+}

src/slack/monitor/events/interactions.ts

@@ -2,6 +2,7 @@ import type { SlackActionMiddlewareArgs } from "@slack/bolt";
 import type { Block, KnownBlock } from "@slack/web-api";
 import type { SlackMonitorContext } from "../context.js";
 import { enqueueSystemEvent } from "../../../infra/system-events.js";
+import { parseSlackModalPrivateMetadata } from "../../modal-metadata.js";
 
 // Prefix for OpenClaw-generated action IDs to scope our handler
 const OPENCLAW_ACTION_PREFIX = "openclaw:";
@@ -47,12 +48,6 @@ type ModalInputSummary = {
   inputValue?: string;
 };
 
-type ModalPrivateMetadata = {
-  sessionKey?: string;
-  channelId?: string;
-  channelType?: string;
-};
-
 function readOptionValues(options: unknown): string[] | undefined {
   if (!Array.isArray(options)) {
     return undefined;
@@ -152,35 +147,11 @@ function summarizeViewState(values: unknown): ModalInputSummary[] {
   return entries;
 }
 
-function parseModalPrivateMetadata(raw: unknown): ModalPrivateMetadata {
-  if (typeof raw !== "string" || raw.trim().length === 0) {
-    return {};
-  }
-  try {
-    const parsed = JSON.parse(raw) as Record<string, unknown>;
-    const sessionKey =
-      typeof parsed.sessionKey === "string" && parsed.sessionKey.trim().length > 0
-        ? parsed.sessionKey
-        : undefined;
-    const channelId =
-      typeof parsed.channelId === "string" && parsed.channelId.trim().length > 0
-        ? parsed.channelId
-        : undefined;
-    const channelType =
-      typeof parsed.channelType === "string" && parsed.channelType.trim().length > 0
-        ? parsed.channelType
-        : undefined;
-    return { sessionKey, channelId, channelType };
-  } catch {
-    return {};
-  }
-}
-
 function resolveModalSessionRouting(params: {
   ctx: SlackMonitorContext;
   privateMetadata: unknown;
 }): { sessionKey: string; channelId?: string; channelType?: string } {
-  const metadata = parseModalPrivateMetadata(params.privateMetadata);
+  const metadata = parseSlackModalPrivateMetadata(params.privateMetadata);
   if (metadata.sessionKey) {
     return { sessionKey: metadata.sessionKey };
   }