refactor(cli): use IoHelper in internal APIs (#209)

This PR is a lot. There is no good way of reviewing it, so thanks for
taking the time.

The main change here is the usage of the `IoHelper` in all internal
APIs. Previously we would pass an `IoHost` and an `action` around as
pair, but separate value. Instead we now use the `IoHelper` which knows
how to send messages with an action.

I also decided to rename all properties and params respectively. This is
partly what makes the PR so large. Note that all changes are to private
APIs.

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

Author: mrgrain

packages/@aws-cdk/tmp-toolkit-helpers/src/api/io/private/io-helper.ts

@@ -13,7 +13,6 @@ export type ActionLessRequest<T, U> = Omit<IoRequest<T, U>, 'action'>;
  * Wraps a client provided IoHost and provides additional features & services to toolkit internal classes.
  */
 export interface IoHelper extends IIoHost {
-  action: ToolkitAction;
   notify<T>(msg: ActionLessMessage<T>): Promise<void>;
   requestResponse<T, U>(msg: ActionLessRequest<T, U>): Promise<U>;
 }
@@ -23,7 +22,6 @@ export interface IoHelper extends IIoHost {
  */
 export function asIoHelper(ioHost: IIoHost, action: ToolkitAction): IoHelper {
   return {
-    action,
     notify: async <T>(msg: Omit<IoMessage<T>, 'action'>) => {
       await ioHost.notify({
         ...msg,

packages/@aws-cdk/toolkit-lib/lib/api/cloud-assembly/private/context-aware-source.ts

@@ -43,13 +43,13 @@ export class ContextAwareCloudAssembly implements ICloudAssemblySource {
   private canLookup: boolean;
   private context: Context;
   private contextFile: string;
-  private ioHost: IoHelper;
+  private ioHelper: IoHelper;
 
   constructor(private readonly source: ICloudAssemblySource, private readonly props: ContextAwareCloudAssemblyProps) {
     this.canLookup = props.lookups ?? true;
     this.context = props.context;
     this.contextFile = props.contextFile ?? PROJECT_CONTEXT; // @todo new feature not needed right now
-    this.ioHost = props.services.ioHost;
+    this.ioHelper = props.services.ioHelper;
   }
 
   /**
@@ -77,22 +77,22 @@ export class ContextAwareCloudAssembly implements ICloudAssemblySource {
 
         let tryLookup = true;
         if (previouslyMissingKeys && equalSets(missingKeysSet, previouslyMissingKeys)) {
-          await this.ioHost.notify(IO.CDK_ASSEMBLY_I0240.msg('Not making progress trying to resolve environmental context. Giving up.', { missingKeys }));
+          await this.ioHelper.notify(IO.CDK_ASSEMBLY_I0240.msg('Not making progress trying to resolve environmental context. Giving up.', { missingKeys }));
           tryLookup = false;
         }
 
         previouslyMissingKeys = missingKeysSet;
 
         if (tryLookup) {
-          await this.ioHost.notify(IO.CDK_ASSEMBLY_I0241.msg('Some context information is missing. Fetching...', { missingKeys }));
+          await this.ioHelper.notify(IO.CDK_ASSEMBLY_I0241.msg('Some context information is missing. Fetching...', { missingKeys }));
           await contextproviders.provideContextValues(
             assembly.manifest.missing,
             this.context,
             this.props.services.sdkProvider,
           );
 
           // Cache the new context to disk
-          await this.ioHost.notify(IO.CDK_ASSEMBLY_I0042.msg(`Writing updated context to ${this.contextFile}...`, {
+          await this.ioHelper.notify(IO.CDK_ASSEMBLY_I0042.msg(`Writing updated context to ${this.contextFile}...`, {
             contextFile: this.contextFile,
             context: this.context.all,
           }));

packages/@aws-cdk/toolkit-lib/lib/api/cloud-assembly/private/prepare-source.ts

@@ -38,7 +38,7 @@ export function determineOutputDirectory(outdir?: string) {
  * @param context The context key/value bash.
  */
 export async function prepareDefaultEnvironment(services: ToolkitServices, props: { outdir?: string } = {}): Promise<Env> {
-  const logFn = (msg: string, ...args: any) => services.ioHost.notify(IO.CDK_ASSEMBLY_I0010.msg(format(msg, ...args)));
+  const logFn = (msg: string, ...args: any) => services.ioHelper.notify(IO.CDK_ASSEMBLY_I0010.msg(format(msg, ...args)));
   const env = await oldPrepare(services.sdkProvider, logFn);
 
   if (props.outdir) {

packages/@aws-cdk/toolkit-lib/lib/api/cloud-assembly/private/source-builder.ts

@@ -65,7 +65,7 @@ export abstract class CloudAssemblySourceBuilder {
             return assembly;
           }
 
-          return assemblyFromDirectory(assembly.directory, services.ioHost, props.loadAssemblyOptions);
+          return assemblyFromDirectory(assembly.directory, services.ioHelper, props.loadAssemblyOptions);
         },
       },
       contextAssemblyProps,
@@ -89,8 +89,8 @@ export abstract class CloudAssemblySourceBuilder {
       {
         produce: async () => {
           // @todo build
-          await services.ioHost.notify(IO.CDK_ASSEMBLY_I0150.msg('--app points to a cloud assembly, so we bypass synth'));
-          return assemblyFromDirectory(directory, services.ioHost, props.loadAssemblyOptions);
+          await services.ioHelper.notify(IO.CDK_ASSEMBLY_I0150.msg('--app points to a cloud assembly, so we bypass synth'));
+          return assemblyFromDirectory(directory, services.ioHelper, props.loadAssemblyOptions);
         },
       },
       contextAssemblyProps,
@@ -139,17 +139,17 @@ export abstract class CloudAssemblySourceBuilder {
                 eventPublisher: async (type, line) => {
                   switch (type) {
                     case 'data_stdout':
-                      await services.ioHost.notify(IO.CDK_ASSEMBLY_I1001.msg(line));
+                      await services.ioHelper.notify(IO.CDK_ASSEMBLY_I1001.msg(line));
                       break;
                     case 'data_stderr':
-                      await services.ioHost.notify(IO.CDK_ASSEMBLY_E1002.msg(line));
+                      await services.ioHelper.notify(IO.CDK_ASSEMBLY_E1002.msg(line));
                       break;
                   }
                 },
                 extraEnv: envWithContext,
                 cwd: props.workingDirectory,
               });
-              return assemblyFromDirectory(outdir, services.ioHost, props.loadAssemblyOptions);
+              return assemblyFromDirectory(outdir, services.ioHelper, props.loadAssemblyOptions);
             });
           } finally {
             await lock?.release();

packages/@aws-cdk/toolkit-lib/lib/toolkit/private/index.ts

@@ -9,7 +9,7 @@ import type { IoHelper } from '../../api/shared-private';
  */
 export interface ToolkitServices {
   sdkProvider: SdkProvider;
-  ioHost: IoHelper;
+  ioHelper: IoHelper;
 }
 
 /**