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overlookmotel
a4478e960a
Add `oxc-codegen` package - a printer written in TS. ### Features - Prints JS, JSX, TS, TSX. - Matches `oxc_codegen` exactly on all Test262, TypeScript, Acorn-JSX fixtures. - Very fast. ### Deficiencies - Pretty-printing only (no compact/minified output). - No support for printing comments. - Source map support is semi-there, but largely untested, and poor API (design doc has some ideas on how to improve it). ### This PR adds - The printer code. - Conformance testing infra. - Further tests for edge cases. - README. - Design doc - how it differs from `oxc_codegen` and why, what produces the perf. ### This PR doesn't add - Not integrated into CI or release pipeline. ### Notes This started as a slop port of `oxc_codegen`. I've iterated on that base, cleaned it up a lot, and at least skimmed through all of it. I think it's in fairly decent shape. The design doc is I think worth a read. It explains the rationale for the choices, in particular the "1 codebase, 4 builds" approach. I've put it in a new top-level directory called `packages`. It's not an app, so didn't seem to me to fit alongside `apps/oxlint` and `apps/oxfmt`. It's pure JS, so not like e.g. `napi/parser`. And it felt too heavyweight to put into `npm` dir. But maybe there's a better place for it. Co-authored-by: Cameron <cameron.clark@hey.com>
48 lines
1.6 KiB
TypeScript
48 lines
1.6 KiB
TypeScript
// Assertions.
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//
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// Both of these are compiled away - `tsdown_plugins/remove_asserts.ts` removes every call to them,
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// and the expressions inside it, so neither costs a release build anything at all.
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/**
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* Assert a value is of a certain type.
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*
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* Has no runtime effect - only for guiding the type-checker.
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* Minification removes this function and all calls to it, so it has zero runtime cost.
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*
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* @param value - Value
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*/
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// oxlint-disable-next-line no-unused-vars
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export function typeAssertIs<T>(value: unknown): asserts value is T {}
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/**
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* Assert a condition.
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*
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* In release builds, is a no-op. Only does runtime checks in debug builds.
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* Minification removes this function and all calls to it in release builds, so it has zero runtime cost.
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*
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* Use this for testing conditions which would indicate a bug in the code.
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* Do NOT use this for validating user input.
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*
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* If creating the error message is expensive, or potentially creating the message itself can result in an error
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* when the assertion passes, pass a function which returns the message.
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*
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* ```ts
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* debugAssert(condition, () => `Condition failed: ${getErrorMessage()}`);
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* ```
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*
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* @param condition - Condition which is expected to be `true`
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* @param message - Message to include in error if condition is `false`,
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* or a function which returns the message to include in error if condition is `false` (optional).
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*/
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export function debugAssert(
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condition: boolean,
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message?: string | (() => string),
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): asserts condition {
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if (!DEBUG) return;
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if (!condition) {
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if (typeof message === "function") message = message();
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throw new Error(message ?? "Assertion failed");
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}
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}
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