feat: deno platform

.vscode/settings.json

@@ -5,6 +5,21 @@
   "typescript.enablePromptUseWorkspaceTsdk": true,
   "editor.formatOnSave": true,
   "editor.defaultFormatter": "dprint.dprint",
+  "[markdown]": {
+    "editor.defaultFormatter": "dprint.dprint"
+  },
+  "[javascript]": {
+    "editor.defaultFormatter": "dprint.dprint"
+  },
+  "[javascriptreact]": {
+    "editor.defaultFormatter": "dprint.dprint"
+  },
+  "[typescript]": {
+    "editor.defaultFormatter": "dprint.dprint"
+  },
+  "[typescriptreact]": {
+    "editor.defaultFormatter": "dprint.dprint"
+  },
   "editor.formatOnSaveMode": "file",
   "editor.codeActionsOnSave": {
     "source.fixAll.oxc": "explicit"
@@ -23,5 +38,7 @@
   "editor.suggestSelection": "recentlyUsed",
   "editor.wordBasedSuggestions": "matchingDocuments",
   "editor.parameterHints.enabled": true,
-  "files.insertFinalNewline": true
+  "files.insertFinalNewline": true,
+  "deno.enable": true,
+  "deno.lint": false
 }

deno.json

@@ -1,8 +1,13 @@
 {
   "$schema": "https://raw.githubusercontent.com/denoland/deno/refs/heads/main/cli/schemas/config-file.v1.json",
   "nodeModulesDir": "manual",
-  "unstable": ["bare-node-builtins", "node-globals"],
-  "workspace": ["./packages/*"],
+  "unstable": [
+    "bare-node-builtins",
+    "node-globals"
+  ],
+  "workspace": [
+    "./packages/*"
+  ],
   "exclude": [
     "**/*.mjs",
     "**/*.cjs",

packages/effect/src/Layer.ts

@@ -25,7 +25,6 @@ import type * as Exit from "./Exit.ts"
 import type { LazyArg } from "./Function.ts"
 import { constant, constTrue, constUndefined, dual, identity } from "./Function.ts"
 import * as internalEffect from "./internal/effect.ts"
-import type { ErrorWithStackTraceLimit } from "./internal/tracer.ts"
 import * as internalTracer from "./internal/tracer.ts"
 import { type Pipeable, pipeArguments } from "./Pipeable.ts"
 import { hasProperty } from "./Predicate.ts"
@@ -1690,10 +1689,10 @@ export const mock =
           if (prop in target) {
             return target[prop as keyof S]
           }
-          const prevLimit = (Error as ErrorWithStackTraceLimit).stackTraceLimit
-          ;(Error as ErrorWithStackTraceLimit).stackTraceLimit = 2
+          const prevLimit = Error.stackTraceLimit
+          Error.stackTraceLimit = 2
           const error = new Error(`${service.key}: Unimplemented method "${prop.toString()}"`)
-          ;(Error as ErrorWithStackTraceLimit).stackTraceLimit = prevLimit
+          Error.stackTraceLimit = prevLimit
           error.name = "UnimplementedError"
           return makeUnimplemented(error)
         },

packages/effect/src/ServiceMap.ts

@@ -16,7 +16,6 @@ import { constant, dual, type LazyArg } from "./Function.ts"
 import * as Hash from "./Hash.ts"
 import type { Inspectable } from "./Inspectable.ts"
 import { exitSucceed, PipeInspectableProto, withFiber, YieldableProto } from "./internal/core.ts"
-import type { ErrorWithStackTraceLimit } from "./internal/tracer.ts"
 import * as Option from "./Option.ts"
 import type { Pipeable } from "./Pipeable.ts"
 import { hasProperty } from "./Predicate.ts"
@@ -145,11 +144,10 @@ export const Service: {
     >
     & { readonly make: Make }
 } = function() {
-  const prevLimit = (Error as ErrorWithStackTraceLimit).stackTraceLimit
-  ;(Error as ErrorWithStackTraceLimit)
-    .stackTraceLimit = 2
+  const prevLimit = Error.stackTraceLimit
+  Error.stackTraceLimit = 2
   const err = new Error()
-  ;(Error as ErrorWithStackTraceLimit).stackTraceLimit = prevLimit
+  Error.stackTraceLimit = prevLimit
   function KeyClass() {}
   const self = KeyClass as any as Types.Mutable<Reference<any>>
   Object.setPrototypeOf(self, ServiceProto)

packages/effect/src/internal/effect.ts

@@ -90,7 +90,7 @@ import {
 } from "./core.ts"
 import * as doNotation from "./doNotation.ts"
 import * as InternalMetric from "./metric.ts"
-import { addSpanStackTrace, type ErrorWithStackTraceLimit, makeStackCleaner } from "./tracer.ts"
+import { addSpanStackTrace, makeStackCleaner } from "./tracer.ts"
 import { version } from "./version.ts"
 
 // ----------------------------------------------------------------------------
@@ -310,9 +310,8 @@ export const causePrettyErrors = <E>(self: Cause.Cause<E>): Array<Error> => {
   const interrupts: Array<Cause.Interrupt> = []
   if (self.failures.length === 0) return errors
 
-  const prevStackLimit = (Error as ErrorWithStackTraceLimit).stackTraceLimit
-  ;(Error as ErrorWithStackTraceLimit)
-    .stackTraceLimit = 1
+  const prevStackLimit = Error.stackTraceLimit
+  Error.stackTraceLimit = 1
 
   for (const failure of self.failures) {
     if (failure._tag === "Interrupt") {
@@ -336,7 +335,7 @@ export const causePrettyErrors = <E>(self: Cause.Cause<E>): Array<Error> => {
     errors.push(causePrettyError(error, interrupts[0].annotations))
   }
 
-  ;(Error as ErrorWithStackTraceLimit).stackTraceLimit = prevStackLimit
+  Error.stackTraceLimit = prevStackLimit
   return errors
 }
 

packages/effect/src/internal/tracer.ts

@@ -1,9 +1,5 @@
 import type * as Tracer from "../Tracer.ts"
 
-export interface ErrorWithStackTraceLimit {
-  stackTraceLimit?: number | undefined
-}
-
 /** @internal */
 export const addSpanStackTrace = <A extends Tracer.TraceOptions>(
   options: A | undefined
@@ -13,10 +9,10 @@ export const addSpanStackTrace = <A extends Tracer.TraceOptions>(
   } else if (options?.captureStackTrace !== undefined && typeof options.captureStackTrace !== "boolean") {
     return options
   }
-  const limit = (Error as ErrorWithStackTraceLimit).stackTraceLimit
-  ;(Error as ErrorWithStackTraceLimit).stackTraceLimit = 3
+  const limit = Error.stackTraceLimit
+  Error.stackTraceLimit = 3
   const traceError = new Error()
-  ;(Error as ErrorWithStackTraceLimit).stackTraceLimit = limit
+  Error.stackTraceLimit = limit
   return {
     ...options,
     captureStackTrace: spanCleaner(() => traceError.stack)

packages/effect/src/unstable/http/FetchHttpClient.ts

@@ -29,7 +29,15 @@ export class RequestInit extends ServiceMap.Service<RequestInit, globalThis.Requ
 const fetch: HttpClient.HttpClient = HttpClient.make((request, url, signal, fiber) => {
   const fetch = fiber.getRef(Fetch)
   const options: globalThis.RequestInit = fiber.services.mapUnsafe.get(RequestInit.key) ?? {}
-  const headers = options.headers ? Headers.merge(Headers.fromInput(options.headers), request.headers) : request.headers
+  const headers = options.headers ?
+    Headers.merge(
+      Headers.fromInput(
+        // TODO: Handle Deno correctly
+        options.headers as ReadonlyArray<[string, string]>
+      ),
+      request.headers
+    ) :
+    request.headers
   const send = (body: BodyInit | undefined) =>
     Effect.map(
       Effect.tryPromise({

packages/effect/src/unstable/workers/Transferable.ts

@@ -153,5 +153,8 @@ export const MessagePort: Transferable<Schema.declare<MessagePort>> = schema(
  */
 export const Uint8Array: Transferable<Schema.Uint8Array> = schema(
   Schema.Uint8Array,
-  (_) => [_.buffer]
+  (_) => [
+    // TODO: Support SharedArrayBuffer in Schema
+    _.buffer as ArrayBuffer
+  ]
 )

packages/platform-deno/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 Effectful Technologies Inc
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/platform-deno/README.md

@@ -0,0 +1,7 @@
+# `@effect/platform-deno`
+
+Provides Deno-specific implementations for the abstractions defined in [`@effect/platform`](https://github.com/Effect-TS/effect/tree/main/packages/platform), allowing you to write platform-independent code that runs smoothly in Deno environments.
+
+## Documentation
+
+- **API Reference**: [View the full documentation](https://effect-ts.github.io/effect/docs/platform-deno).

packages/platform-deno/docgen.json

@@ -0,0 +1,20 @@
+{
+  "$schema": "../../node_modules/@effect/docgen/schema.json",
+  "srcLink": "https://github.com/Effect-TS/effect/tree/main/packages/platform-deno/src/",
+  "exclude": ["src/internal/**/*.ts"],
+  "examplesCompilerOptions": {
+    "noEmit": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "moduleResolution": "NodeNext",
+    "module": "NodeNext",
+    "target": "ES2022",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "rewriteRelativeImportExtensions": true,
+    "allowImportingTsExtensions": true,
+    "paths": {
+      "effect": ["../../../effect/src/index.js"],
+      "effect/*": ["../../../effect/src/*.js"]
+    }
+  }
+}

packages/platform-deno/package.json

@@ -0,0 +1,74 @@
+{
+  "name": "@effect/platform-deno",
+  "type": "module",
+  "version": "0.77.6",
+  "license": "MIT",
+  "description": "Platform specific implementations for the Deno runtime",
+  "homepage": "https://effect.website",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/Effect-TS/effect-smol.git",
+    "directory": "packages/platform-deno"
+  },
+  "bugs": {
+    "url": "https://github.com/Effect-TS/effect-smol/issues"
+  },
+  "tags": [
+    "deno",
+    "typescript",
+    "algebraic-data-types",
+    "functional-programming"
+  ],
+  "keywords": [
+    "deno",
+    "typescript",
+    "algebraic-data-types",
+    "functional-programming"
+  ],
+  "engines": {
+    "deno": ">=2.5.0"
+  },
+  "sideEffects": [],
+  "exports": {
+    "./package.json": "./package.json",
+    ".": "./src/index.ts",
+    "./*": "./src/*.ts",
+    "./internal/*": null,
+    "./*/index": null
+  },
+  "files": [
+    "src/**/*.ts",
+    "dist/**/*.js",
+    "dist/**/*.js.map",
+    "dist/**/*.d.ts",
+    "dist/**/*.d.ts.map"
+  ],
+  "publishConfig": {
+    "provenance": true,
+    "exports": {
+      "./package.json": "./package.json",
+      ".": "./dist/index.js",
+      "./*": "./dist/*.js",
+      "./internal/*": null,
+      "./*/index": null
+    }
+  },
+  "scripts": {
+    "codegen": "build-utils prepare-v4",
+    "build": "tsc -b tsconfig.build.json && babel dist --plugins annotate-pure-calls --out-dir dist --source-maps",
+    "check": "deno check",
+    "test": "vitest",
+    "coverage": "vitest --coverage"
+  },
+  "dependencies": {
+    "@std/path": "jsr:^1.1.4"
+  },
+  "peerDependencies": {
+    "effect": "workspace:^"
+  },
+  "devDependencies": {
+    "@types/deno": "^2.5.0",
+    "@std/assert": "jsr:^1.0.16",
+    "effect": "workspace:^"
+  }
+}

packages/platform-deno/src/DenoKeyValueStore.ts

@@ -0,0 +1,50 @@
+/**
+ * This module exposes database primitives.
+ * @module
+ *
+ * @since 1.0.0
+ */
+
+import * as Layer from "effect/Layer"
+import * as KeyValueStore from "effect/unstable/persistence/KeyValueStore"
+import { makeKvStore } from "./internal/kv.ts"
+
+/**
+ * Creates a {@linkcode KeyValueStore} layer that uses the Web-native {@linkcode localStorage} API.
+ *
+ * Values are stored between sessions.
+ *
+ * @since 1.0.0
+ * @category layer
+ */
+export const layerLocalStorage: Layer.Layer<KeyValueStore.KeyValueStore> = KeyValueStore.layerStorage(() =>
+  localStorage
+)
+
+/**
+ * Creates a {@linkcode KeyValueStore} layer that uses the Web-native {@linkcode sessionStorage} API.
+ *
+ * Values are stored only for the current session.
+ *
+ * @since 1.0.0
+ * @category layer
+ */
+export const layerSessionStorage: Layer.Layer<KeyValueStore.KeyValueStore> = KeyValueStore.layerStorage(() =>
+  sessionStorage
+)
+
+/**
+ * Creates a {@linkcode KeyValueStore} layer that uses Deno’s cloud-native {@linkcode Deno.Kv} API.
+ *
+ * @remarks
+ * This does not support gradual adoption,
+ * and will fail semi-gracefully on non-`string` or {@linkcode Uint8Array} values.
+ * kvStore
+ * @since 1.0.0
+ * @category layer
+ */
+export const layerKv: Layer.Layer<KeyValueStore.KeyValueStore> = Layer.effect(
+  KeyValueStore.KeyValueStore
+)(
+  makeKvStore()
+)