From e611144e090db446218263e7753ba49f620d453a Mon Sep 17 00:00:00 2001
From: Ryan Bas <ryanbas21@gmail.com>
Date: Mon, 11 May 2026 22:28:03 -0600
Subject: [PATCH] refactor: use Schema.TaggedStruct for discriminated unions

Replace Schema.Struct with _tag literal fields with
Schema.TaggedStruct, the idiomatic Effect pattern for
discriminated unions. Silences TS34 language service warnings
and enables optimized union decoding.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .../src/lib/auth-event.schema.ts              | 24 +++++++------------
 packages/treeshake-check/src/lib/schemas.ts   |  6 ++---
 2 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/packages/devtools-types/src/lib/auth-event.schema.ts b/packages/devtools-types/src/lib/auth-event.schema.ts
index f7be7ba..74865de 100644
--- a/packages/devtools-types/src/lib/auth-event.schema.ts
+++ b/packages/devtools-types/src/lib/auth-event.schema.ts
@@ -38,8 +38,7 @@ export const CorsFlagSchema = Schema.Struct({
 
 export type CorsFlag = Schema.Schema.Type<typeof CorsFlagSchema>;
 
-export const NetworkDataSchema = Schema.Struct({
-  _tag: Schema.Literal('network'),
+export const NetworkDataSchema = Schema.TaggedStruct('network', {
   url: Schema.String,
   method: Schema.String,
   status: Schema.Number,
@@ -63,8 +62,7 @@ export const SdkAuthorizationSchema = Schema.Struct({
   state: Schema.optional(Schema.String),
 });
 
-export const SdkDataSchema = Schema.Struct({
-  _tag: Schema.Literal('sdk'),
+export const SdkDataSchema = Schema.TaggedStruct('sdk', {
   nodeStatus: Schema.String,
   previousStatus: Schema.optional(Schema.String),
   interactionId: Schema.optional(Schema.String),
@@ -82,26 +80,22 @@ export const SdkDataSchema = Schema.Struct({
   responseBody: Schema.optional(Schema.Unknown),
 });
 
-export const SdkConfigDataSchema = Schema.Struct({
-  _tag: Schema.Literal('sdk-config'),
+export const SdkConfigDataSchema = Schema.TaggedStruct('sdk-config', {
   config: Schema.Unknown,
 });
 
-export const DomDataSchema = Schema.Struct({
-  _tag: Schema.Literal('dom'),
+export const DomDataSchema = Schema.TaggedStruct('dom', {
   element: Schema.optional(Schema.String),
   url: Schema.optional(Schema.String),
 });
 
-export const SessionDataSchema = Schema.Struct({
-  _tag: Schema.Literal('session'),
+export const SessionDataSchema = Schema.TaggedStruct('session', {
   key: Schema.String,
   before: Schema.optional(Schema.String),
   after: Schema.optional(Schema.String),
 });
 
-export const JourneyDataSchema = Schema.Struct({
-  _tag: Schema.Literal('journey'),
+export const JourneyDataSchema = Schema.TaggedStruct('journey', {
   stepType: Schema.Union(
     Schema.Literal('Step'),
     Schema.Literal('LoginSuccess'),
@@ -120,8 +114,7 @@ export const JourneyDataSchema = Schema.Struct({
   errorReason: Schema.optional(Schema.String),
 });
 
-export const OidcDataSchema = Schema.Struct({
-  _tag: Schema.Literal('oidc'),
+export const OidcDataSchema = Schema.TaggedStruct('oidc', {
   phase: Schema.Union(
     Schema.Literal('authorize'),
     Schema.Literal('exchange'),
@@ -164,8 +157,7 @@ export const OidcErrorSchema = Schema.Struct({
   errorDescription: Schema.optional(Schema.String),
 });
 
-export const OidcSemanticsSchema = Schema.Struct({
-  _tag: Schema.Literal('oidc-semantics'),
+export const OidcSemanticsSchema = Schema.TaggedStruct('oidc-semantics', {
   oidcPhase: Schema.Union(
     Schema.Literal('discovery'),
     Schema.Literal('authorize'),
diff --git a/packages/treeshake-check/src/lib/schemas.ts b/packages/treeshake-check/src/lib/schemas.ts
index 5836aa2..ae858c3 100644
--- a/packages/treeshake-check/src/lib/schemas.ts
+++ b/packages/treeshake-check/src/lib/schemas.ts
@@ -86,12 +86,10 @@ export type PackageJsonHints = typeof PackageJsonHints.Type;
 // ─── Top-level result ────────────────────────────────────────────────────────
 
 export const TreeshakeResult = Schema.Union(
-  Schema.Struct({
-    _tag: Schema.Literal('FullyTreeshakeable'),
+  Schema.TaggedStruct('FullyTreeshakeable', {
     hints: PackageJsonHints,
   }),
-  Schema.Struct({
-    _tag: Schema.Literal('HasSideEffects'),
+  Schema.TaggedStruct('HasSideEffects', {
     totalOriginalBytes: Schema.Number,
     totalRenderedBytes: Schema.Number,
     modules: Schema.Array(ModuleAnalysis),