Normalize error message grammar (TS/JS)

[irbull]

There are a variety of different ways errors in Deno's TS/JS layer are raised. Some are sentence case, others not. Some end with a period, others do not. Some provide the current state of the system, others do not.

Without a standard error guide, it makes it hard for new contributors to determine how to format error message. Furthermore, without a standard error guide, it makes it hard for users to know what to expect.

We just went through the std and normalized the errors there. We should do the same with the JavaScript / TypeScript code in the cli / runtime. There is an issue about improving error messages in the cli [1] which is orthogonal to this.

I think we should start with the Error Guide used in the std and see if that's a good fit for the JavaScript / TypeScript code in the cli [2].

[1] #24699
[2] denoland/std#5574

[irbull]

I wrote a small Deno script to scan the directories of the deno/deno project and determine which folders have JS/TS files and which of those files throw . I excluded /node_modules/, /testdata/, /tests/, ./github/, /bench, and /tsc. Here is what I found:

Folder	Throws	Status	PR
./cli/js	32	✅	#25406
./ext/broadcast_channel	2	✅	No obvious problems found
./ext/cache	5	✅	#25310
./ext/canvas	2	✅	#25310
./ext/console	3	✅	#25301
./ext/cron	5	✅	#25300
./ext/crypto	226	✅	#25440
./ext/fetch	46	✅	#25374
./ext/ffi	5	✅	#25310
./ext/fs	14	⏳	#25414
./ext/http	37	✅	#25496
./ext/io	0	✅	No obvious problems found
./ext/kv	24	✅	#25500
./ext/net	26	⛔
./ext/node/polyfills	288	⛔
./ext/node/polyfills/_fs	73	⛔
./ext/node/polyfills/_process	3	⛔
./ext/node/polyfills/_util	20	⛔
./ext/node/polyfills/assert	1	⛔
./ext/node/polyfills/dns	0	✅	No obvious problems found
./ext/node/polyfills/fs	0	✅	No obvious problems found
./ext/node/polyfills/internal	31	⛔
./ext/node/polyfills/internal/crypto	91	⛔
./ext/node/polyfills/internal/dns	6	⛔
./ext/node/polyfills/internal/fs	0	✅	No obvious problems found
./ext/node/polyfills/internal/process	0	✅	No obvious problems found
./ext/node/polyfills/internal/test	0	✅	No obvious problems found
./ext/node/polyfills/internal/util	2	⛔
./ext/node/polyfills/internal/util/parse_args	9	⛔
./ext/node/polyfills/internal_binding	9	⛔
./ext/node/polyfills/path	9	⛔
./ext/node/polyfills/readline	0	✅	No obvious problems found
./ext/node/polyfills/stream	0	✅	No obvious problems found
./ext/node/polyfills/timers	0	✅	No obvious problems found
./ext/node/polyfills/util	0	✅	No obvious problems found
./ext/url	3	⛔
./ext/web	138	⛔
./ext/webgpu	35	✅	#25719
./ext/webidl	38	✅	#25625
./ext/websocket	14	✅	#25622
./ext/websocket/autobahn	0	✅	No obvious problems found
./ext/webstorage	0	✅	No obvious problems found
./runtime/examples/extension	0	✅	No obvious problems found
./runtime/js	46	✅	#25563
./tools	17	✅	Folder only contains internal tools
./tools/napi	0	✅	No obvious problems found
./tools/release	4	⛔

Script: https://gist.github.com/irbull/a16232d1a96ee3023501baf48b17a7e9

[oles]

I'd say something like https://github.com/denoland/std/blob/main/.github/CONTRIBUTING.md#error-messages would be a nice addition to the Deno Style Guide!

Good job on the Standard Library, @irbull!

[irbull]

Thanks for the kind words @oles. I've proposed a PR to the deno style guide with the same formatting used in the std. denoland/docs#759

I'm putting together a few change-sets that update the JS/TS code in the runtime so we can see how we feel about that here too.