chore: simplify WORKSPACE

This means we don't have to mirror hashes an extra time when we add a new swc version.
Move this to the documentation instead.
Note, this means we don't have test coverage for these two attributes anymore.
If we really want that we could add another e2e for it.

Author: alexeagle

WORKSPACE

@@ -12,18 +12,11 @@ load("//swc:dependencies.bzl", "rules_swc_dependencies")
 # Fetch our "runtime" dependencies which users need as well
 rules_swc_dependencies()
 
-load("//swc:repositories.bzl", "swc_register_toolchains")
+load("//swc:repositories.bzl", "LATEST_VERSION", "swc_register_toolchains")
 
 swc_register_toolchains(
     name = "swc",
-    # Demonstrates how users can choose ANY swc version, not just the ones we mirrored
-    integrity_hashes = {
-        "darwin-arm64": "sha384-IhP/76Zi5PEfsrGwPJj/CLHu2afxSBO2Fehp/qo4uHVXez08dcfyd9UzrcUI1z1q",
-        "darwin-x64": "sha384-s2wH7hzaMbTbIkgPpP5rAYThH/+H+RBQ/5xKbpM4lfwPMS6cNBIpjKVnathrENm/",
-        "linux-arm64-gnu": "sha384-iaBhMLrnHTSfXa86AVHM6zHqYbH3Fh1dWwDeH7sW9HKvX2gbQb6LOpWN6Wp4ddud",
-        "linux-x64-gnu": "sha384-R/y9mcodpNt8l6DulUCG5JsNMrApP+vOAAh3bTRChh6LQKP0Z3Fwq86ztfObpAH8",
-    },
-    swc_version_from = "//:package.json",
+    swc_version = LATEST_VERSION,
 )
 
 load("@aspect_bazel_lib//lib:repositories.bzl", "aspect_bazel_lib_dependencies", "register_jq_toolchains")

docs/repositories.md

@@ -1,6 +1,51 @@
 """Repository rules for fetching the swc toolchain.
 
 For typical usage, see the snippets provided in the rules_swc release notes.
+
+### Version matching
+
+To keep the swc version in sync with non-Bazel tooling, use `swc_version_from`.
+
+Currently this only works when a single, pinned version appears, see:
+https://github.com/aspect-build/rules_ts/issues/308
+
+For example, `package.json`:
+
+```json
+{
+  "devDependencies": {
+    "@swc/core": "1.3.37"
+  }
+}
+```
+
+Allows this in `WORKSPACE`:
+
+```starlark
+swc_register_toolchains(
+    name = "swc",
+    swc_version_from = "//:package.json",
+)
+```
+
+### Other versions
+
+To use an swc version which is not mirrored to rules_swc, use `integrity_hashes`.
+
+For example in `WORKSPACE`:
+
+```starlark
+swc_register_toolchains(
+    name = "swc",
+    integrity_hashes = {
+        "darwin-arm64": "sha384-IhP/76Zi5PEfsrGwPJj/CLHu2afxSBO2Fehp/qo4uHVXez08dcfyd9UzrcUI1z1q",
+        "darwin-x64": "sha384-s2wH7hzaMbTbIkgPpP5rAYThH/+H+RBQ/5xKbpM4lfwPMS6cNBIpjKVnathrENm/",
+        "linux-arm64-gnu": "sha384-iaBhMLrnHTSfXa86AVHM6zHqYbH3Fh1dWwDeH7sW9HKvX2gbQb6LOpWN6Wp4ddud",
+        "linux-x64-gnu": "sha384-R/y9mcodpNt8l6DulUCG5JsNMrApP+vOAAh3bTRChh6LQKP0Z3Fwq86ztfObpAH8",
+    },
+    swc_version = "1.3.37",
+)
+```
 """
 
 load("@bazel_skylib//lib:versions.bzl", "versions")
@@ -13,9 +58,9 @@ LATEST_VERSION = TOOL_VERSIONS.keys()[0]
 _DOC = "Fetch external dependencies needed to run the SWC cli"
 _ATTRS = {
     "swc_version": attr.string(doc = "Explicit version. If provided, the package.json is not read."),
-    "swc_version_from": attr.label(doc = "Location of package.json which may have a version for @swc/core."),
+    "swc_version_from": attr.label(doc = "Location of package.json which has a version for @swc/core."),
     "platform": attr.string(mandatory = True, values = PLATFORMS.keys()),
-    "integrity_hashes": attr.string_dict(),
+    "integrity_hashes": attr.string_dict(doc = "A mapping from platform to integrity hash."),
 }
 
 # This package is versioned the same as the underlying rust binary we download