fix(project): reader keeps one commit per visit after an absent file (G-A2 follow-up)

libs/datatug/main/src/lib/project/new-project/new-project-form.component.spec.ts

@@ -2,11 +2,12 @@ import { CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
 import { ComponentFixture, TestBed } from '@angular/core/testing';
 import { PopoverController } from '@ionic/angular';
 import { ErrorLogger } from '@sneat/core';
-import { Subject, of } from 'rxjs';
+import { Subject, of, throwError } from 'rxjs';
 
 import { NewProjectFormComponent } from './new-project-form.component';
 import { DatatugNavService } from '../../services/nav/datatug-nav.service';
 import { ProjectService } from '../../services/project/project.service';
+import { GithubRepoError } from '../../services/repo/github/github-api';
 import { GithubProjectCreateService } from '../../services/repo/github/github-project-create.service';
 import { GithubOAuthService } from '../../services/repo/github/github-oauth.service';
 import { GithubReposService } from '../../services/repo/github/github-repos.service';
@@ -337,6 +338,50 @@ describe('NewProjectFormComponent creating in a GitHub repo', () => {
     );
   });
 
+  it('shows what GitHub did not return when it made the repository but sent no default branch', () => {
+    oauth.isSignedIn = true;
+    oauth.accessToken = 'gho_token';
+    (component as unknown as { selectedRepo: { set: (v: string) => void } }).selectedRepo.set(
+      '__new__',
+    );
+    component.newRepoName = 'my-projects';
+    repos.createRepo = vi.fn(() =>
+      throwError(
+        () =>
+          new GithubRepoError(
+            'default-branch',
+            'GitHub created my-projects, but did not return the default branch of my-projects, so DataTug cannot tell which branch to commit to.',
+          ),
+      ),
+    );
+    component.store = 'github';
+
+    component.create();
+
+    expect(formErrorOf(component)).toContain('did not return the default branch');
+    expect(createProject).not.toHaveBeenCalled();
+  });
+
+  it('shows what GitHub did not return when the chosen repository has no default branch', () => {
+    oauth.isSignedIn = true;
+    oauth.accessToken = 'gho_token';
+    (component as unknown as { selectedRepo: { set: (v: string) => void } }).selectedRepo.set(
+      'datatug/demo-projects',
+    );
+    component.store = 'github';
+    component.title = 'My project';
+
+    component.create();
+    createProject$.error(
+      new GithubRepoError(
+        'default-branch',
+        'GitHub did not return the default branch of datatug/demo-projects, so DataTug cannot tell which branch to commit to.',
+      ),
+    );
+
+    expect(formErrorOf(component)).toContain('did not return the default branch');
+  });
+
   it('requires a name before creating a new repository', () => {
     oauth.isSignedIn = true;
     oauth.accessToken = 'gho_token';

libs/datatug/main/src/lib/project/new-project/new-project-form.component.ts

@@ -25,7 +25,10 @@ import { IProjectContext, parseDatatugStoreRef } from '../../nav/nav-models';
 import { DatatugNavService } from '../../services/nav/datatug-nav.service';
 import { DatatugServicesProjectModule } from '../../services/project/datatug-services-project.module';
 import { ProjectService } from '../../services/project/project.service';
-import { IGithubRepo } from '../../services/repo/github/github-api';
+import {
+  GithubRepoError,
+  IGithubRepo,
+} from '../../services/repo/github/github-api';
 import {
   GithubOAuthService,
   GithubSignInRedirecting,
@@ -249,7 +252,9 @@ export class NewProjectFormComponent implements ViewDidEnter {
           error: (err) => {
             this.isCreating.set(false);
             this.formError.set(
-              `Failed to create the repository "${name}" on GitHub.`,
+              err instanceof GithubRepoError
+                ? err.message
+                : `Failed to create the repository "${name}" on GitHub.`,
             );
             this.errorLogger.logError(err, 'Failed to create a GitHub repo');
           },
@@ -283,7 +288,9 @@ export class NewProjectFormComponent implements ViewDidEnter {
         error: (err) => {
           this.isCreating.set(false);
           this.formError.set(
-            `Failed to create the project in ${fullName}. Check that your GitHub access allows writing to it.`,
+            err instanceof GithubRepoError
+              ? err.message
+              : `Failed to create the project in ${fullName}. Check that your GitHub access allows writing to it.`,
           );
           this.errorLogger.logError(
             err,

libs/datatug/main/src/lib/services/repo/datatug-store.service.github.spec.ts

@@ -52,7 +52,7 @@ describe('DatatugStoreGithubService.watchProjectItem', () => {
   function createService(getRawJson: ReturnType<typeof vi.fn>) {
     TestBed.configureTestingModule({
       providers: [
-        { provide: GithubProjectReaderService, useValue: { getRawJson } },
+        { provide: GithubProjectReaderService, useValue: { getRawJson, visitEpoch: () => '0.0' } },
       ],
     });
     return TestBed.inject(DatatugStoreGithubService);
@@ -113,7 +113,7 @@ describe('DatatugStoreGithubService.getProjectSummary: ids it cannot read', () =
   function createService(getRawJson: ReturnType<typeof vi.fn>) {
     TestBed.configureTestingModule({
       providers: [
-        { provide: GithubProjectReaderService, useValue: { getRawJson } },
+        { provide: GithubProjectReaderService, useValue: { getRawJson, visitEpoch: () => '0.0' } },
       ],
     });
     return TestBed.inject(DatatugStoreGithubService);
@@ -143,7 +143,11 @@ describe('DatatugStoreGithubService.getProjectSummary: reads through the reader
       providers: [
         {
           provide: GithubProjectReaderService,
-          useValue: { getRawJson, readInfo: () => of({ state }) },
+          useValue: {
+            getRawJson,
+            visitEpoch: () => '0.0',
+            readInfo: () => of({ state }),
+          },
         },
       ],
     });
@@ -170,3 +174,41 @@ describe('DatatugStoreGithubService.getProjectSummary: reads through the reader
     expect((error as GithubProjectNotFoundError).reason).toBe(state);
   });
 });
+
+describe('DatatugStoreGithubService.getProjectSummary: the summary follows the commit of the reader', () => {
+  it('a summary read before the reader moved to another commit is read again, once; until it moves again it is kept', () => {
+    let epoch = '0.0';
+    let title = 'at the old commit';
+    const getRawJson = vi.fn(() => of({ id: 'r@o@d', title }));
+    TestBed.configureTestingModule({
+      providers: [
+        {
+          provide: GithubProjectReaderService,
+          useValue: { getRawJson, visitEpoch: () => epoch },
+        },
+      ],
+    });
+    const service = TestBed.inject(DatatugStoreGithubService);
+    const titles: string[] = [];
+    const read = () =>
+      service
+        .getProjectSummary('r@o@d')
+        .subscribe((p) => titles.push(p.title as string));
+
+    read();
+    read();
+    expect(getRawJson).toHaveBeenCalledTimes(1);
+
+    epoch = '0.1'; // the visit moved to another commit
+    title = 'at the new commit';
+    read();
+    read();
+    expect(getRawJson).toHaveBeenCalledTimes(2);
+    expect(titles).toEqual([
+      'at the old commit',
+      'at the old commit',
+      'at the new commit',
+      'at the new commit',
+    ]);
+  });
+});

libs/datatug/main/src/lib/services/repo/datatug-store.service.github.ts

@@ -1,7 +1,7 @@
 import { IFolder, IFolderItem } from '../../models/definition/folder';
 import { IProjectSummary } from '../../models/definition/project';
 import { IDatatugStoreService } from './datatug-store.service.interface';
-import { Observable, defer, of, throwError } from 'rxjs';
+import { Observable, of, throwError } from 'rxjs';
 import { map, shareReplay, switchMap } from 'rxjs/operators';
 import { Injectable, inject } from '@angular/core';
 import {
@@ -34,9 +34,11 @@ export class DatatugStoreGithubService implements IDatatugStoreService {
   // reads the project summary (for its `boards` list), so without this a
   // page that renders both the project summary AND the folder tabs (the
   // project page itself) would fetch `datatug-project.json` twice.
+  // Kept with the reader's `visitEpoch` at the time: a summary read at a commit the visit has since moved away from
+  // (the reader asked GitHub again about a commit it only remembered, and was told another) is not served again.
   private readonly summaryCache = new Map<
     string,
-    Observable<IProjectSummary>
+    { readonly epoch: string; readonly summary: Observable<IProjectSummary> }
   >();
 
   /**
@@ -55,58 +57,57 @@ export class DatatugStoreGithubService implements IDatatugStoreService {
   }
 
   getProjectSummary(projectId: string): Observable<IProjectSummary> {
-    let cached = this.summaryCache.get(projectId);
-    if (cached) {
-      return cached;
+    const cached = this.summaryCache.get(projectId);
+    if (cached && cached.epoch === this.githubReader.visitEpoch(projectId)) {
+      return cached.summary;
     }
     try {
       assertReadableGithubProjectId(projectId);
     } catch (err) {
       return throwError(() => err);
     }
+    const epoch = this.githubReader.visitEpoch(projectId);
 
     // Through the reader: the same commit as the listing and every other file, one cache, one request (the old
     // second, separate read of this file could come from a different commit than the rest of the page).
-    // `defer`: `shareReplay` drops a failed read and the next subscriber reads again, instead of getting the same
+    // The reader's observable is lazy (a read starts on subscription, a failed one is read again by the next
+    // subscriber), and `shareReplay` drops a failed read: the next subscriber reads again, instead of getting the same
     // failure back until the page is reloaded.
-    cached = defer(() =>
-      this.githubReader.getRawJson<IProjectSummary>(
-        projectId,
-        'datatug-project.json',
-      ),
-    ).pipe(
-      switchMap((p) =>
-        p
-          ? of(p)
-          : this.githubReader
-              .readInfo(projectId)
-              .pipe(
-                switchMap((info) =>
-                  throwError(
-                    () =>
-                      new GithubProjectNotFoundError(
-                        projectId,
-                        info.state === 'moved' ? 'moved' : 'missing',
-                      ),
+    const summary = this.githubReader
+      .getRawJson<IProjectSummary>(projectId, 'datatug-project.json')
+      .pipe(
+        switchMap((p) =>
+          p
+            ? of(p)
+            : this.githubReader
+                .readInfo(projectId)
+                .pipe(
+                  switchMap((info) =>
+                    throwError(
+                      () =>
+                        new GithubProjectNotFoundError(
+                          projectId,
+                          info.state === 'moved' ? 'moved' : 'missing',
+                        ),
+                    ),
                   ),
                 ),
-              ),
-      ),
-      map((p) => {
-        if (p.id === projectId) {
-          return p;
-        }
-        if (p.id) {
-          console.warn(
-            `Request project info with projectId=${projectId} but response JSON have id=${p.id}`,
-          );
-        }
-        return { ...p, id: projectId };
-      }),
-      shareReplay(1),
-    );
-    this.summaryCache.set(projectId, cached);
-    return cached;
+        ),
+        map((p) => {
+          if (p.id === projectId) {
+            return p;
+          }
+          if (p.id) {
+            console.warn(
+              `Request project info with projectId=${projectId} but response JSON have id=${p.id}`,
+            );
+          }
+          return { ...p, id: projectId };
+        }),
+        shareReplay(1),
+      );
+    this.summaryCache.set(projectId, { epoch, summary });
+    return summary;
   }
 
   /**