fix(types): Require TypeScript 4.0; remove broken TS 3.x declarations

.changeset/drop-typescript-3.md

@@ -0,0 +1,19 @@
+---
+'@data-client/core': minor
+'@data-client/endpoint': minor
+'@data-client/normalizr': minor
+'@data-client/react': minor
+'@data-client/graphql': minor
+'@data-client/img': minor
+'@data-client/test': minor
+---
+
+BREAKING: Require TypeScript 4.0 or later
+
+The TypeScript 3.x type declarations are removed. They no longer type-checked on any TypeScript 3.x version, and
+`@data-client/rest` already required TypeScript 4.0. Upgrade TypeScript to 4.0 or later.
+
+```diff title="package.json"
+- "typescript": "^3.9.0"
++ "typescript": "^4.0.0"
+```

.cursor/rules/ci-config.mdc

@@ -14,7 +14,7 @@ alwaysApply: false
   - `tests` (lint, typecheck, unit_tests, node_matrix): false only when every changed path is docs/website/tooling (`website/`, `docs/`, `.changeset/`, `.cursor/`, `.agents/`, `.claude/`, `.github/`, root `*.md`), except `website/src/components/Playground/` (has unit tests). When both flags are false, `setup` halts before install.
 - Legacy TS types (`ci:build:legacy-types`, consumed by `esmodule-types`):
   - Built inside `setup` (`ci:build:setup:esmodule`) only when the esmodule flag is set; there is no separate job, to keep a job hop off the critical path.
-  - In CI only endpoint/normalizr/rest outputs for TS >= 4.0 are built (`LEGACY_MIN_TS=4.0`, the oldest TS in the `esmodule-types` matrix); release builds (`build:types`) still emit every version.
+  - CI builds the endpoint, normalizr and rest legacy outputs, all for TS >= 4.0 (the minimum supported TS, and the oldest in the `esmodule-types` matrix). `use-enhanced-reducer` still ships a `ts3.4` build in release builds (`build:types`).
   - `scripts/build-legacy-types.sh` builds each TS version concurrently; each `ts<version>/` gets the downleveled `lib` (with `abstract new` rewritten to `new` below 4.2, which `downlevel-dts` misses), then every newer version's `src-*-types` overlay, then its own. Keep overlays to small single-purpose modules (like `NoInfer.ts`, `tupleTypes.ts`) so whole-file copies can't go stale.
   - `esmodule-types` also runs `examples/todo-app/tsconfig.typetest-libcheck.json` (`skipLibCheck: false`, `types: []`) so errors inside the legacy outputs fail CI, and `esmodule-types-latest` runs it with `--moduleResolution bundler` (TS 7 removed `node`) to cover `lib/`; the other typetests use `skipLibCheck: true`.
   - Any change to legacy types building must leave `ts*/` output byte-identical to master (diff it) unless it intentionally changes published types (then add a changeset).

docs/core/getting-started/installation.md

@@ -57,9 +57,9 @@ Install the [Vue plugin](https://vuejs.org/guide/reusability/plugins.html) when
 ## Supported Tools
 
 <details>
-<summary><b>TypeScript 3.7+</b></summary>
+<summary><b>TypeScript 4.0+</b></summary>
 
-TypeScript is optional, but requires at least version [3.7](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#more-recursive-type-aliases) and [strictNullChecks](https://www.typescriptlang.org/tsconfig#strictNullChecks) for full type enforcement.
+TypeScript is optional, but requires at least version [4.0](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-0.html#variadic-tuple-types) and [strictNullChecks](https://www.typescriptlang.org/tsconfig#strictNullChecks) for full type enforcement.
 
 </details>
 

package.json

@@ -27,7 +27,7 @@
     "ci:build:setup:esmodule": "run-p ci:build:types-and-legacy ci:build-test-lib",
     "ci:build:types-and-legacy": "yarn ci:build:types && yarn ci:build:legacy-types",
     "ci:build:types": "yarn build:copy:ambient && tsc --build --builders 1",
-    "ci:build:legacy-types": "LEGACY_MIN_TS=4.0 yarn workspaces foreach -Wpiv --include @data-client/endpoint --include @data-client/normalizr --include @data-client/rest run build:legacy-types",
+    "ci:build:legacy-types": "yarn workspaces foreach -Wpiv --include @data-client/endpoint --include @data-client/normalizr --include @data-client/rest run build:legacy-types",
     "ci:build-test-lib": "yarn workspace @data-client/core run build:lib && yarn workspace @data-client/test run build:lib && yarn workspace @data-client/test run build:bundle",
     "ci:build:esmodule": "yarn workspaces foreach -WptivR --from @data-client/react --from @data-client/rest --from @data-client/graphql run build:lib && yarn workspace @data-client/normalizr run build:js:node && yarn workspace @data-client/endpoint run build:js:node",
     "ci:build:bundlesize": "yarn workspaces foreach -Wptiv --no-private run build:lib && yarn workspace test-bundlesize run build:sizecompare",

packages/core/package.json

@@ -22,20 +22,6 @@
       "*": [
         "lib/index.d.ts"
       ]
-    },
-    ">=3.4": {
-      "": [
-        "ts3.4/index.d.ts"
-      ],
-      "next": [
-        "ts3.4/next/index.d.ts"
-      ],
-      "mock": [
-        "ts3.4/mock/index.d.ts"
-      ],
-      "*": [
-        "ts3.4/index.d.ts"
-      ]
     }
   },
   "exports": {
@@ -70,7 +56,6 @@
     "src",
     "dist",
     "lib",
-    "ts3.4",
     "node.mjs",
     "legacy",
     "LICENSE",
@@ -83,7 +68,6 @@
     "build:js:browser": "BROWSERSLIST_ENV=legacy yarn g:rollup",
     "build:bundle": "yarn g:runs build:js:\\* && echo '{\"type\":\"commonjs\"}' > dist/package.json",
     "build:clean": "yarn g:clean ./index.d.ts",
-    "build:legacy-types": "yarn g:downtypes lib ts3.4",
     "build": "run build:lib && run build:legacy:lib && run build:bundle",
     "dev": "run build:lib -w",
     "prepare": "run build:lib",

packages/core/tsconfig.compile.json

@@ -1,4 +1,4 @@
 {
   "extends": "./tsconfig",
-  "exclude": ["node_modules", "dist", "lib", "legacy", "ts3.4", "src-legacy-types", "**/__tests__"]
+  "exclude": ["node_modules", "dist", "lib", "legacy", "**/__tests__"]
 }

packages/endpoint/.gitignore

@@ -2,7 +2,6 @@
 /dist
 /legacy
 /index.d.ts
-/ts3.4
 /ts4.0
 /ts4.2
 /ts4.8

packages/endpoint/package.json

@@ -68,14 +68,6 @@
       "*": [
         "ts4.0/index.d.ts"
       ]
-    },
-    ">=3.4": {
-      "": [
-        "ts3.4/index.d.ts"
-      ],
-      "*": [
-        "ts3.4/index.d.ts"
-      ]
     }
   },
   "exports": {
@@ -101,21 +93,20 @@
     "ts4.8",
     "ts4.2",
     "ts4.0",
-    "ts3.4",
     "node.mjs",
     "legacy",
     "LICENSE",
     "README.md"
   ],
   "scripts": {
-    "build:lib": "NODE_ENV=production BROWSERSLIST_ENV='2020' POLYFILL_TARGETS='chrome>88,safari>14' yarn g:babel --out-dir lib --ignore 'src/schemas-3.7'",
-    "build:legacy:lib": "NODE_ENV=production BROWSERSLIST_ENV='2018' POLYFILL_TARGETS='chrome>80,safari>13,firefox>72' yarn g:babel --out-dir legacy --ignore 'src/schemas-3.7'",
+    "build:lib": "NODE_ENV=production BROWSERSLIST_ENV='2020' POLYFILL_TARGETS='chrome>88,safari>14' yarn g:babel --out-dir lib",
+    "build:legacy:lib": "NODE_ENV=production BROWSERSLIST_ENV='2018' POLYFILL_TARGETS='chrome>80,safari>13,firefox>72' yarn g:babel --out-dir legacy",
     "build:js:node": "BROWSERSLIST_ENV=node12 yarn g:rollup && echo '{\"type\":\"commonjs\"}' > dist/package.json",
     "build:js:browser": "BROWSERSLIST_ENV=legacy yarn g:rollup",
     "build:bundle": "yarn g:runs build:js:\\*",
-    "build:clean": "yarn g:clean ts3.4 ts4.0 ts4.2 ts4.8",
+    "build:clean": "yarn g:clean ts4.0 ts4.2 ts4.8",
     "build": "run build:lib && run build:legacy:lib && run build:bundle",
-    "build:legacy-types": "yarn g:legacy-types 4.8 4.2 4.0 3.4",
+    "build:legacy-types": "yarn g:legacy-types 4.8 4.2 4.0",
     "dev": "run build:lib -w",
     "prepare": "run build:lib",
     "prepack": "run prepare && run build:bundle && run build:legacy:lib",

packages/endpoint/tsconfig.compile.json

@@ -4,5 +4,5 @@
     "skipLibCheck": true
   },
   "include": ["src"],
-  "exclude": ["node_modules", "dist", "lib", "legacy", "ts3.4", "**/__tests__"]
+  "exclude": ["node_modules", "dist", "lib", "legacy", "**/__tests__"]
 }

packages/graphql/package.json

@@ -54,14 +54,6 @@
       "*": [
         "lib/index.d.ts"
       ]
-    },
-    ">=3.4": {
-      "": [
-        "ts3.4/index.d.ts"
-      ],
-      "*": [
-        "ts3.4/index.d.ts"
-      ]
     }
   },
   "exports": {
@@ -86,7 +78,6 @@
     "lib",
     "node.mjs",
     "legacy",
-    "ts3.4",
     "LICENSE",
     "README.md"
   ],
@@ -97,7 +88,6 @@
     "build:js:browser": "BROWSERSLIST_ENV=legacy yarn g:rollup",
     "build:bundle": "yarn g:runs build:js:\\* && echo '{\"type\":\"commonjs\"}' > dist/package.json",
     "build:clean": "yarn g:clean index.d.ts",
-    "build:legacy-types": "yarn g:downtypes lib ts3.4",
     "build": "run build:lib && run build:legacy:lib && run build:bundle",
     "dev": "run build:lib -w",
     "prepare": "run build:lib",

packages/graphql/tsconfig.compile.json

@@ -1,4 +1,4 @@
 {
   "extends": "./tsconfig",
-  "exclude": ["node_modules", "dist", "lib", "legacy", "ts3.4", "**/__tests__"]
+  "exclude": ["node_modules", "dist", "lib", "legacy", "**/__tests__"]
 }

packages/img/package.json

@@ -36,14 +36,6 @@
       "*": [
         "lib/index.d.ts"
       ]
-    },
-    ">=3.4": {
-      "": [
-        "ts3.4/index.d.ts"
-      ],
-      "*": [
-        "ts3.4/index.d.ts"
-      ]
     }
   },
   "type": "module",
@@ -54,7 +46,6 @@
     "src",
     "dist",
     "lib",
-    "ts3.4",
     "LICENSE",
     "README.md"
   ],
@@ -64,7 +55,6 @@
     "build:js:browser": "BROWSERSLIST_ENV=legacy yarn g:rollup",
     "build:bundle": "yarn g:runs build:js:\\* && echo '{\"type\":\"commonjs\"}' > dist/package.json",
     "build:clean": "yarn g:clean",
-    "build:legacy-types": "yarn g:downtypes lib ts3.4",
     "build": "run build:lib && run build:bundle",
     "dev": "run build:lib -w",
     "prepare": "run build:lib",

packages/img/tsconfig.compile.json

@@ -5,5 +5,5 @@
       "@data-client/img/*": ["./src/*"]
     }
   },
-  "exclude": ["node_modules", "dist", "lib", "ts3.4", "**/__tests__"]
+  "exclude": ["node_modules", "dist", "lib", "**/__tests__"]
 }

packages/normalizr/.gitignore

@@ -2,6 +2,5 @@
 /dist
 /legacy
 /index.d.ts
-/ts3.4
 /ts4.0
 /ts4.1