fix: refresh mcp server functionality (#1349)

Author: chungjac

server/aws-lsp-codewhisperer/src/language-server/agenticChat/tools/mcp/mcpManager.test.ts

@@ -647,3 +647,49 @@ describe('close()', () => {
         expect(() => McpManager.instance).to.throw()
     })
 })
+
+// reinitializeMcpServers()
+describe('reinitializeMcpServers()', () => {
+    let loadStub: sinon.SinonStub
+
+    beforeEach(() => {
+        loadStub = sinon.stub(mcpUtils, 'loadMcpServerConfigs')
+    })
+
+    afterEach(async () => {
+        sinon.restore()
+        try {
+            await McpManager.instance.close()
+        } catch {}
+    })
+
+    it('calls necessary methods during reinitialization', async () => {
+        const cfg: MCPServerConfig = {
+            command: 'cmd',
+            args: [],
+            env: {},
+            disabled: false,
+            autoApprove: false,
+            toolOverrides: {},
+            __configPath__: 'cfg.json',
+        }
+        loadStub.resolves(new Map([['srv', cfg]]))
+
+        const mgr = await McpManager.init(['cfg.json'], features)
+
+        const closeStub = sinon.stub(mgr, 'close').resolves()
+        const initStub = sinon.stub(McpManager, 'init').resolves(mgr)
+
+        loadStub.resetHistory()
+
+        await mgr.reinitializeMcpServers()
+
+        expect(closeStub.calledOnce).to.be.true
+        expect(initStub.calledOnce).to.be.true
+        expect(initStub.firstCall.args[0]).to.deep.equal(['cfg.json'])
+        expect(initStub.firstCall.args[1]).to.equal(features)
+
+        closeStub.restore()
+        initStub.restore()
+    })
+})

server/aws-lsp-codewhisperer/src/language-server/agenticChat/tools/mcp/mcpManager.ts

@@ -413,6 +413,26 @@ export class McpManager {
         McpManager.#instance = undefined
     }
 
+    /**
+     * Reinitialize all MCP servers by closing existing connections and rediscovering servers
+     */
+    public async reinitializeMcpServers(): Promise<void> {
+        this.features.logging.info('Reinitializing MCP servers')
+
+        try {
+            await this.close()
+            await McpManager.init(this.configPaths, this.features)
+
+            const reinitializedServerCount = McpManager.#instance?.mcpServers.size
+            this.features.logging.info(
+                `MCP servers reinitialized completed. Total servers: ${reinitializedServerCount}`
+            )
+        } catch (err: any) {
+            this.features.logging.error(`Error reinitializing MCP servers: ${err.message}`)
+            throw err
+        }
+    }
+
     /**
      * Check if a tool requires approval.
      */