(core) Miscellaneous little logging improvements

Summary:
1. Log errors in `ActiveDoc.loadDoc` as errors, not just warnings, except for a common 'Cannot create fork' error caused by deployment tests.

2. Log the method name that had an error in `server/lib/Client.ts`.

Discussion: https://grist.slack.com/archives/CR8HZ4P9V/p1652364998893169

Following up on https://phab.getgrist.com/D3522

Test Plan: tested manually, particularly by running the nbrowser/Fork test that led to the initial noisy errors in Slack.

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D3525

app/server/lib/ActiveDoc.ts

@@ -644,6 +644,8 @@ export class ActiveDoc extends EventEmitter {
         });
       });
     } catch (err) {
+      const level = err.status === 404 ? "warn" : "error";
+      this._log.log(level, docSession, "Failed to load document", err);
       await this.shutdown();
       throw err;
     }

app/server/lib/Client.ts

@@ -456,7 +456,8 @@ export class Client {
           (typeof code === 'string' && code.startsWith('AUTH_NO'))
         );
 
-        this._log.warn(null, "Error %s %s", skipStack ? err : err.stack, code || '');
+        this._log.warn(null, "Responding to method %s with error: %s %s",
+          request.method, skipStack ? err : err.stack, code || '');
         response = {reqId: request.reqId, error: err.message};
         if (err.code) {
           response.errorCode = err.code;

app/server/lib/HostedStorageManager.ts

@@ -1,4 +1,5 @@
 import * as sqlite3 from '@gristlabs/sqlite3';
+import {ApiError} from 'app/common/ApiError';
 import {mapGetOrSet} from 'app/common/AsyncCreate';
 import {delay} from 'app/common/delay';
 import {DocEntry} from 'app/common/DocListAPI';
@@ -596,9 +597,9 @@ export class HostedStorageManager implements IDocStorageManager {
         // skip S3, just use file system
         let present: boolean = await fse.pathExists(this.getPath(docName));
         if ((forkId || snapshotId) && !present) {
-          if (!canCreateFork) { throw new Error(`Cannot create fork`); }
+          if (!canCreateFork) { throw new ApiError("Document fork not found", 404); }
           if (snapshotId && snapshotId !== 'current') {
-            throw new Error(`cannot find snapshot ${snapshotId} of ${docName}`);
+            throw new ApiError(`cannot find snapshot ${snapshotId} of ${docName}`, 404);
           }
           if (await fse.pathExists(this.getPath(trunkId))) {
             await fse.copy(this.getPath(trunkId), this.getPath(docName));
@@ -681,10 +682,10 @@ export class HostedStorageManager implements IDocStorageManager {
     if (!await this._ext.exists(destIdWithoutSnapshot)) {
       if (!options.trunkId) { return false; }   // Document not found in S3
       // No such fork in s3 yet, try from trunk (if we are allowed to create the fork).
-      if (!options.canCreateFork) { throw new Error('Cannot create fork'); }
+      if (!options.canCreateFork) { throw new ApiError("Document fork not found", 404); }
       // The special NEW_DOCUMENT_CODE trunk means we should create an empty document.
       if (options.trunkId === NEW_DOCUMENT_CODE) { return false; }
-      if (!await this._ext.exists(options.trunkId)) { throw new Error('Cannot find original'); }
+      if (!await this._ext.exists(options.trunkId)) { throw new ApiError('Cannot find original', 404); }
       sourceDocId = options.trunkId;
     }
     await this._ext.downloadTo(sourceDocId, destId, this.getPath(destId), options.snapshotId);

test/nbrowser/Fork.ts

@@ -330,12 +330,12 @@ describe("Fork", function() {
         await altSession.loadDoc(`/doc/${doc.id}~${forkId}~${userId}`, false);
 
         assert.equal(await driver.findWait('.test-modal-dialog', 2000).isDisplayed(), true);
-        assert.match(await driver.find('.test-modal-dialog').getText(), /Cannot create fork/);
+        assert.match(await driver.find('.test-modal-dialog').getText(), /Document fork not found/);
 
         // Ensure the user has a way to report the problem (although including the report button in
         // the modal might be better).
         assert.match(await driver.find('.test-notifier-toast-wrapper').getText(),
-                     /Cannot create fork.*Report a problem/s);
+                     /Document fork not found.*Report a problem/s);
 
         // A new doc cannot be created either (because of access
         // mismatch - for forks of the doc used in these tests, user2
@@ -350,7 +350,7 @@ describe("Fork", function() {
         const anonSession = await altSession.anon.login();
         await anonSession.loadDoc(`/doc/${doc.id}~${forkId}~${userId}`, false);
         assert.equal(await driver.findWait('.test-modal-dialog', 2000).isDisplayed(), true);
-        assert.match(await driver.find('.test-modal-dialog').getText(), /Cannot create fork/);
+        assert.match(await driver.find('.test-modal-dialog').getText(), /Document fork not found/);
 
         // A new doc cannot be created either (because of access mismatch).
         await altSession.loadDoc(`/doc/new~${forkId}~${userId}`, false);
@@ -362,12 +362,12 @@ describe("Fork", function() {
         await team.login();
         await team.loadDoc(`/doc/${doc.id}~${forkId}~${userId}`, false);
         assert.equal(await driver.findWait('.test-modal-dialog', 2000).isDisplayed(), true);
-        assert.match(await driver.find('.test-modal-dialog').getText(), /Cannot create fork/);
+        assert.match(await driver.find('.test-modal-dialog').getText(), /Document fork not found/);
 
         // New document can no longer be casually created this way anymore either.
         await team.loadDoc(`/doc/new~${forkId}~${userId}`, false);
         assert.equal(await driver.findWait('.test-modal-dialog', 2000).isDisplayed(), true);
-        assert.match(await driver.find('.test-modal-dialog').getText(), /Cannot create fork/);
+        assert.match(await driver.find('.test-modal-dialog').getText(), /Document fork not found/);
         await gu.wipeToasts();
       });