feat(bundler): implement enum inlining / more constant folding

[paperclover]

Initially was a PR to fix an enum bug, but it turned out the bug was due to a lack of a feature: enum inlining. So I decided to do it, since it was a feature I personally have a big use for (For example, the bun.report project has a regex hack workaround to force enum inlining, because the codegen otherwise is an abomination).

edit: As time went, this PR turned into not just that, but a lot of changes to constant folding. i am much happier with how the bundler handles this now.

Fixes #11764
Fixes #2945
Fixes #2889
Fixes #12285
Fixes
Draft TODO:

• e_inlined_enum
• inline enum as well as in simplify functions
• Enum use-before-define behavior
• Implement required changes in TS namespaces
• Fix sibling namespace scopes
• Cross-file enums while bundling
• Tests
• Note: late-stage numeric folding (js printer) is not implemented, and will not be for now

extras:

• constnat folding now happens with all numeric operators
• constant folding now happens with n + "baa", where n is any constant number. this uses webkit's code to properly adhere to JS spec
• constant folding now happens with +"1.2". this uses webkit's code to properly adhere to JS spec
• constant folding requires --minify-syntax, where previously it seemed to always be applied. Though keep in mind the JS runtime transpiles all files with --minify-syntax
• constant folding is now enabled in the context of require, import, and macro calls; even if minify-syntax is disabled. This was previously not an issue because it was always enabled.
• string and template string folding is much more advanced now. this may need more tests

---

Simple Sample

enum A {
  Hello = 1,
  World,
}

console.log(A.Hello);
console.log(A.World);
console.log(A.Hello + A.World);

After:

// index.ts
console.log(1 /* Hello */);
console.log(2 /* World */);
console.log(3);

Before:

// index.ts
var A;
(function(A2) {
  A2[A2["Hello"] = 1] = "Hello";
  A2[A2["World"] = 2] = "World";
})(A || (A = {}));
console.log(A.Hello);
console.log(A.World);
console.log(A.Hello + A.World);

---

If you reference the enum directly, you can get the two-way map. This even works with const enum, as it is TSC's job to prohibit such usage.

enum A {
  Hello = 1,
  World,
}

console.log(A);

The codegen of these enums have been improved. Projects with heavy enum usage should see smaller bundle sizes. Now:

var A;
((A2) => {
  A2[A2.Hello = 1] = "Hello";
  A2[A2.World = 2] = "World";
})(A ||= {});

Before:

// index.ts
var A;
(function(A2) {
  A2[A2["Hello"] = 1] = "Hello";
  A2[A2["World"] = 2] = "World";
})(A || (A = {}));
console.log(A);

It would be interesting as a future project to see if the size of these enums could be shrunk further, but esbuild doesn't do that, and I think personally it's fine to leave enum in the dust as const enum and inlining all values becomes the new norm.

[github-actions]

❌ @Jarred-Sumner, your commit has failing tests :(

🐧💪 1 failing tests Linux AARCH64

• test/js/deno/crypto/webcrypto.test.ts 1 failing

🐧🖥 1 failing tests Linux x64 baseline

• test/js/bun/shell/leak.test.ts 1 failing

🪟💻 4 failing tests Windows x64 baseline

• test/cli/install/registry/bun-install-registry.test.ts 1 failing
• test/cli/install/registry/bun-install-windowsshim.test.ts code 1
• test/js/bun/dns/resolve-dns.test.ts SIGKILL
• test/js/node/child_process/child_process.test.ts 1 failing

🪟💻 3 failing tests Windows x64

• test/cli/install/registry/bun-install-registry.test.ts SIGKILL
• test/cli/install/registry/bun-install-windowsshim.test.ts code 1
• test/js/node/child_process/child_process.test.ts 1 failing

View logs

[paperclover]

note: this is renamed from toStringSafely to toString, not because it is now less safe, but because the original intent of "we are taking a safer approach" does not apply.

[paperclover]

apologies for doing a ton of other random things in this pr. i fixed the banned.json linter which resulted in needing to apply a ton of small transformations. i did this because i was sick of std.debug.print showing at all in my cmd+shift+f menu. this also resulted in the deletion of some old files, which some did not even past astgen.

additionally, i have been using a client side spell-checker, so it just becomes annoying to see a ton of yellow underlines. maybe i will upstream a ci check to keep spelling somewhat intact (i have been very impressed with the typos cli and lsp, it is very low false positive).

[paperclover]

comptime @inComptime is a compiler error in 0.14 and in 0.13 does not do what we want.

[paperclover]

this behavior is now provided via BUN_DEBUG_mimalloc=1

[Jarred-Sumner]

Suggested change

	property_accesses: std.StringArrayHashMapUnmanaged(Ref) = .{},
	property_accesses: bun.StringArrayHashMapUnmanaged(Ref) = .{},

[paperclover]

two bugs remain

• utf16 identifiers
• template rope thing

[Jarred-Sumner]

Suggested change

	if (comptime Environment.allow_assert) {
	if (comptime Environment.isDebug) {

[Jarred-Sumner]

What was this change?

[paperclover]

known_enum_values was removed in favor of real enum inlining.

[Jarred-Sumner]

Was this deliberately commented out?

[paperclover]

this second put is seen in esbuild's code but i cannot think of a situation where the value is not already in the map