Regression - 1.34 Insiders tries to open non-existent files in /.vscode folder

[gjsjohnmurray]

A FileSystemProvider extension that provides a /.vscode folder containing only a settings.json file also gets asked by 1.34.0-insider to readFile non-existent files named tasks.json and launch.json from that folder. This does not happen on 1.33.1

Steps to Reproduce:

1. Obtain the MemFS sample (git clone https://github.com/Microsoft/vscode-extension-samples and then go to the fsprovider-sample subdir)
2. In src/extension.ts add the following lines to the function that is registered as implementing the 'memfs.init' command (code pointer)

        // canary .vscode folder with stub settings.json file
        memFs.createDirectory(vscode.Uri.parse(`memfs:/.vscode/`));
        memFs.writeFile(vscode.Uri.parse(`memfs:/.vscode/settings.json`), Buffer.from('{\n}'), { create: true, overwrite: true });

3. At the start of the stat method of the MemFS class in src/fileSystemProvider.ts (code pointer) add a logpoint with the following message: stat {uri.path}
4. At the start of the readFile method (code pointer) add a logpoint with the following message: readFile {uri.path}
5. Launch debugging using the 'Launch Extension' configuration.
6. When the [Extension Development Host] window appears, switch to it and run (e.g. F1) the command MemFS: Setup Workspace followed by the command MemFS: Create Files

Debug Console output from 1.34.0-insider is:

MemFS says "Hello"
MemFS says "Hello"
readFile /.vscode/settings.json
readFile /.vscode/tasks.json
readFile /.vscode/launch.json
readFile /.vscode/settings.json
readFile /.vscode/tasks.json
readFile /.vscode/launch.json
stat /.vscode/settings.json
stat /.vscode/tasks.json
stat /.vscode/launch.json
stat /.vscode/settings.json
stat /.vscode/tasks.json
stat /.vscode/launch.json
stat /.vscode/tasks.json
stat /.vscode/launch.json
stat /.vscode/tasks.json
stat /.vscode/launch.json

Using 1.33.1 the same procedure gives:

MemFS says "Hello"
MemFS says "Hello"
stat /.vscode
stat /.vscode/settings.json
readFile /.vscode/settings.json

Notice how 1.33.1 stats the .vscode folder and its settings.json file before reading the file, whereas 1.34-insider reads that file (twice) and attempts to read the non-existent files tasks.json and launch.json (again, twice), only issuing stat calls on the files afterwards.

VS Code version: Code - Insiders 1.34.0-insider (0fde661, 2019-04-25T05:24:52.804Z)
OS version: Windows_NT x64 10.0.16299

[bpasero]

@sandy081 possibly related to using the file service for configuration?

[gjsjohnmurray]

@bpasero - Maybe related to this, which looks to me like it could result in readFile getting ahead of stat, particularly if the FileSystemProvider doesn't supply an etag string.

[bpasero]

@gjsjohnmurray that should be fine though as both stat and readFile will trigger the ENOTFOUND error, no? I think the question is if previously we used node APIs to do the reading without proper error handling and now through the file service errors are logged AND we go through the file providers.

[gjsjohnmurray]

My FileSystemProvider is derived from RemoteFS, which notifies the user of errors during readFile but is quiet about ones in stat. I guess there may be other extensions out there which aren't going to be happy about this change.

Maybe related, when Insiders opens files served by my extension it appears to succeed (i.e. no errors) but the files display as though they are 0-byte ones. I can reproduce this with the RemoteFS extension connecting using FTP to a couple of different public sites. No such problems with the current 1.33.1 release. I'm about to open a new issue about this.

[bpasero]

@gjsjohnmurray you do not need to notify the user about errors, this is taken care of by the file service in VSCode and in most cases even better because it can put the error in context (e.g. when you follow a link to a file that does not exist we can show an error with a button to create this file).

Do you have a sample I can try to reproduce the second issue you are talking about?

[bpasero]

I can reproduce the many errors popping up on startup:

via the steps in #72909

This is not a very nice user experience, I have to agree.

[sandy081]

IMO, it is totally fine to read the files even if they do not exist.. extension do not need to log or notify such as the caller of the API (in this case me) should handle it.

@bpasero May I know who are logging/prompting these errors?

[bpasero]

@sandy081 actually turns out this is coming from the extension itself and not from us:

https://github.com/liximomo/vscode-remote-fs/blob/88b67ff683a05998d79bd4fb8466f7ca518d0f51/src/helpers/reportError.ts#L6

[gjsjohnmurray]

I'm closing this. I have revised my extension so it no longer outputs these messages. The author of Remote FS might do likewise in the future.