From 65e8bf61f62e9da7fe9dc78980f7379b39e73a59 Mon Sep 17 00:00:00 2001
From: gomes <17035424+gomesalexandre@users.noreply.github.com>
Date: Wed, 19 Aug 2026 09:54:32 +0200
Subject: [PATCH 1/2] test: add tsd type tests for SemVerVersion/SemVerRange
 assignability

closes #73

Adds src/versions.test-d.ts, following the existing .test-d.ts pattern
(hex.test-d.ts, json.test-d.ts, caip-types.test-d.ts), proving the two
opaque SemVer types are not mutually assignable at the type level even
though both are strings at runtime, and that a plain string literal
isn't assignable to either without going through its assertion
function first.
---
 src/versions.test-d.ts | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 src/versions.test-d.ts

diff --git a/src/versions.test-d.ts b/src/versions.test-d.ts
new file mode 100644
index 00000000..d30ed0e8
--- /dev/null
+++ b/src/versions.test-d.ts
@@ -0,0 +1,27 @@
+import { expectAssignable, expectNotAssignable } from 'tsd';
+
+import type { SemVerRange, SemVerVersion } from '.';
+import { assertIsSemVerRange, assertIsSemVerVersion } from '.';
+
+// A value produced via a type's own assertion function is assignable to
+// itself:
+
+const unsafeVersion = '1.0.0';
+assertIsSemVerVersion(unsafeVersion);
+expectAssignable<SemVerVersion>(unsafeVersion);
+
+const unsafeRange = '^1.0.0';
+assertIsSemVerRange(unsafeRange);
+expectAssignable<SemVerRange>(unsafeRange);
+
+// SemVerVersion and SemVerRange are distinct opaque types, and are not
+// mutually assignable, even though both are strings at runtime:
+
+expectNotAssignable<SemVerRange>(unsafeVersion);
+expectNotAssignable<SemVerVersion>(unsafeRange);
+
+// A plain string is not assignable to either opaque type without going
+// through the type's own validation/assertion function:
+
+expectNotAssignable<SemVerVersion>('1.0.0');
+expectNotAssignable<SemVerRange>('^1.0.0');

From d6f39a98710aefa6536299efca64b9c1d248c660 Mon Sep 17 00:00:00 2001
From: gomes <17035424+gomesalexandre@users.noreply.github.com>
Date: Wed, 19 Aug 2026 12:10:06 +0200
Subject: [PATCH 2/2] fix: point test:types at the src test-d files directly

yarn test:types (tsd) has been a silent no-op repo-wide since the
package.json types field became ./dist/index.d.cts. tsd 0.29's
auto-discovery does typingsFile.replace(/\.d\.ts$/, '.test-d.ts'),
which doesn't match .d.cts, so the configured tsd.directory: "src"
fallback never fires - instead globby matches the literal ./dist/index.d.cts
path (which exists once CI builds before running test:types), finds
one file with zero assertions in it, and tsd reports a clean pass on
nothing.

Reproduced: appending a bogus assertion to any existing *.test-d.ts
file still exits 0 under the old script. Fixed by pointing tsd at the
src glob explicitly, matching the tsd.directory config's original
intent. Verified against all 5 existing test-d files (hex, json,
caip-types, misc, versions): clean pass with the fix, and the same
bogus-assertion mutation now correctly fails.
---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 15028861..8608bead 100644
--- a/package.json
+++ b/package.json
@@ -54,7 +54,7 @@
     "prepack": "./scripts/prepack.sh",
     "test": "yarn test:source && yarn test:types",
     "test:source": "jest && jest-it-up",
-    "test:types": "tsd",
+    "test:types": "tsd --files 'src/**/*.test-d.ts'",
     "test:watch": "jest --watch"
   },
   "resolutions": {