Add readLine to Terminal and make columns property an Effect

.changeset/healthy-games-visit.md

@@ -0,0 +1,6 @@
+---
+"@effect/platform-node": patch
+"@effect/platform": patch
+---
+
+add Terminal.readLine to read input line-by-line from the terminal

.changeset/tasty-vans-wink.md

@@ -0,0 +1,6 @@
+---
+"@effect/platform-node": patch
+"@effect/platform": patch
+---
+
+make Terminal.columns an Effect to account for resizing the terminal

packages/platform-bun/examples/http-client.ts

@@ -54,6 +54,5 @@ Effect.flatMap(
 ).pipe(
   Effect.tap(Effect.log),
   Effect.provide(TodoServiceLive),
-  Effect.tapErrorCause(Effect.logError),
   runMain
 )

packages/platform-bun/examples/http-router.ts

@@ -35,6 +35,5 @@ const EnvLive = Layer.merge(ServerLive, NodeContext.layer)
 serve.pipe(
   Effect.scoped,
   Effect.provide(EnvLive),
-  Effect.tapErrorCause(Effect.logError),
   runMain
 )

packages/platform-bun/examples/http-server.ts

@@ -7,6 +7,5 @@ const ServerLive = Http.server.layer({ port: 3000 })
 Http.server.serve(Effect.succeed(Http.response.text("Hello World"))).pipe(
   Effect.scoped,
   Effect.provide(ServerLive),
-  Effect.tapErrorCause(Effect.logError),
   runMain
 )

packages/platform-node/examples/http-client.ts

@@ -54,6 +54,5 @@ Effect.flatMap(
 ).pipe(
   Effect.tap(Effect.log),
   Effect.provide(TodoServiceLive),
-  Effect.tapErrorCause(Effect.logError),
   runMain
 )

packages/platform-node/examples/http-router.ts

@@ -41,6 +41,5 @@ const HttpLive = Layer.scopedDiscard(serve).pipe(
 )
 
 Layer.launch(HttpLive).pipe(
-  Effect.tapErrorCause(Effect.logError),
   runMain
 )

packages/platform-node/examples/http-server.ts

@@ -8,6 +8,5 @@ const ServerLive = Http.server.layer(() => createServer(), { port: 3000 })
 Http.server.serve(Effect.succeed(Http.response.text("Hello World"))).pipe(
   Effect.scoped,
   Effect.provide(ServerLive),
-  Effect.tapErrorCause(Effect.logError),
   runMain
 )

packages/platform-node/examples/terminal.ts

@@ -0,0 +1,23 @@
+import * as Runtime from "@effect/platform-node/Runtime"
+import * as Terminal from "@effect/platform-node/Terminal"
+import { Console, Effect } from "effect"
+
+const program = Effect.gen(function*(_) {
+  const terminal = yield* _(Terminal.Terminal)
+
+  const line1 = yield* _(terminal.readLine)
+  yield* _(Console.log(`First line: ${line1}`))
+
+  const line2 = yield* _(terminal.readLine)
+  yield* _(Console.log(`Second line: ${line2}`))
+
+  const line3 = yield* _(terminal.readLine)
+  yield* _(Console.log(`Third line: ${line3}`))
+})
+
+const MainLive = Terminal.layer
+
+program.pipe(
+  Effect.provide(MainLive),
+  Runtime.runMain
+)

packages/platform-node/src/internal/terminal.ts

@@ -16,40 +16,22 @@ export const make = (
     const input = yield* _(Effect.sync(() => globalThis.process.stdin))
     const output = yield* _(Effect.sync(() => globalThis.process.stdout))
 
-    // Acquire a `readline` interface and use it to force `stdin` to emit
-    // keypress events
-    const acquireReadlineInterface = Effect.sync(() => {
-      const rl = readline.createInterface({ input, escapeCodeTimeout: 50 })
+    // Acquire a readline interface
+    const acquireReadlineInterface = Effect.sync(() =>
+      readline.createInterface({
+        input,
+        escapeCodeTimeout: 50
+      })
+    )
+
+    // Uses the readline interface to force `stdin` to emit keypress events
+    const emitKeypressEvents = (rl: readline.Interface): readline.Interface => {
       readline.emitKeypressEvents(input, rl)
       if (input.isTTY) {
         input.setRawMode(true)
       }
       return rl
-    })
-
-    // Handle the `"keypress"` event emitted by `stdin` forced by `readline`
-    const handleKeypressEvent = Effect.async<never, Terminal.QuitException, Terminal.UserInput>((resume) => {
-      const handleKeypress = (input: string | undefined, key: readline.Key) => {
-        const userInput: Terminal.UserInput = {
-          input: Option.fromNullable(input),
-          key: {
-            name: key.name || "",
-            ctrl: key.ctrl || false,
-            meta: key.meta || false,
-            shift: key.shift || false
-          }
-        }
-        if (shouldQuit(userInput)) {
-          resume(Effect.fail(new Terminal.QuitException()))
-        } else {
-          resume(Effect.succeed(userInput))
-        }
-      }
-      input.once("keypress", handleKeypress)
-      return Effect.sync(() => {
-        input.removeListener("keypress", handleKeypress)
-      })
-    })
+    }
 
     // Close the `readline` interface
     const releaseReadlineInterface = (rl: readline.Interface) =>
@@ -60,9 +42,52 @@ export const make = (
         rl.close()
       })
 
+    // Handle the `"keypress"` event emitted by `stdin` (forced by readline)
+    const handleKeypressEvent = (input: typeof globalThis.process.stdin) =>
+      Effect.async<never, Terminal.QuitException, Terminal.UserInput>((resume) => {
+        const handleKeypress = (input: string | undefined, key: readline.Key) => {
+          const userInput: Terminal.UserInput = {
+            input: Option.fromNullable(input),
+            key: {
+              name: key.name || "",
+              ctrl: key.ctrl || false,
+              meta: key.meta || false,
+              shift: key.shift || false
+            }
+          }
+          if (shouldQuit(userInput)) {
+            resume(Effect.fail(new Terminal.QuitException()))
+          } else {
+            resume(Effect.succeed(userInput))
+          }
+        }
+        input.once("keypress", handleKeypress)
+        return Effect.sync(() => {
+          input.removeListener("keypress", handleKeypress)
+        })
+      })
+
+    // Handle the `"line"` event emitted by the readline interface
+    const handleLineEvent = (rl: readline.Interface) =>
+      Effect.async<never, Terminal.QuitException, string>((resume) => {
+        const handleLine = (line: string) => {
+          resume(Effect.succeed(line))
+        }
+        rl.on("line", handleLine)
+        return Effect.sync(() => {
+          rl.removeListener("line", handleLine)
+        })
+      })
+
     const readInput = Effect.acquireUseRelease(
+      acquireReadlineInterface.pipe(Effect.map(emitKeypressEvents)),
+      () => handleKeypressEvent(input),
+      releaseReadlineInterface
+    )
+
+    const readLine = Effect.acquireUseRelease(
       acquireReadlineInterface,
-      () => handleKeypressEvent,
+      (rl) => handleLineEvent(rl),
       releaseReadlineInterface
     )
 
@@ -84,8 +109,9 @@ export const make = (
 
     return Terminal.Terminal.of({
       // The columns property can be undefined if stdout was redirected
-      columns: output.columns || 0,
+      columns: Effect.sync(() => output.columns || 0),
       readInput,
+      readLine,
       display
     })
   })

packages/platform/src/Terminal.ts

@@ -19,11 +19,15 @@ export interface Terminal {
   /**
    * The number of columns available on the platform's terminal interface.
    */
-  readonly columns: number
+  readonly columns: Effect<never, never, number>
   /**
    * Reads a single input event from the default standard input.
    */
   readonly readInput: Effect<never, QuitException, UserInput>
+  /**
+   * Reads a single line from the default standard input.
+   */
+  readonly readLine: Effect<never, QuitException, string>
   /**
    * Displays text to the the default standard output.
    */