From 59f4994ec56506dd42f23a352fc3a448f53dc620 Mon Sep 17 00:00:00 2001
From: Ian Thomas <ianthomas23@gmail.com>
Date: Fri, 24 May 2024 12:12:32 +0100
Subject: [PATCH] Command output to file

---
 src/file_system.ts         |  2 ++
 src/io/file_output.ts      |  6 +++++-
 src/jupyter_file_system.ts | 23 ++++++++++++++++-------
 src/shell.ts               | 22 ++++++++++++++++++----
 tests/shell.test.ts        | 19 +++++++++++++++++++
 5 files changed, 60 insertions(+), 12 deletions(-)

diff --git a/src/file_system.ts b/src/file_system.ts
index 30b7d22..9b4a6aa 100644
--- a/src/file_system.ts
+++ b/src/file_system.ts
@@ -10,4 +10,6 @@ export interface IFileSystem {
 
   // Assume new file ...
   touch(path: string): Promise<void>
+
+  write(path: string, content: string): Promise<void>
 }
diff --git a/src/io/file_output.ts b/src/io/file_output.ts
index 57f24c9..ae4464f 100644
--- a/src/io/file_output.ts
+++ b/src/io/file_output.ts
@@ -7,11 +7,15 @@ export class FileOutput extends BufferedOutput {
     this.fs = fs
     this.path = path
     this.append = append
+
+    if (this.append) {
+      throw Error("FileOutput in append mode not implemented")
+    }
   }
 
   override async flush(): Promise<void> {
     const all_data = this.data.join()
-    console.log("TO FILE:", this.fs, this.path, this.append, all_data)
+    this.fs.write(this.path, all_data);
     this.clear()
   }
 
diff --git a/src/jupyter_file_system.ts b/src/jupyter_file_system.ts
index 99b2306..a5f8a74 100644
--- a/src/jupyter_file_system.ts
+++ b/src/jupyter_file_system.ts
@@ -18,13 +18,18 @@ export class JupyterFileSystem implements IFileSystem {
   }
 
   async list(path: string): Promise<string[]> {
-    const listing = await this._contentsManager.get(path, { content: true })
-    if (listing.type == "file") {
-      return [listing.name]
-    } else {  // listing.type == "directory"
-      const content = listing.content as Contents.IModel[]
-      const filenames = content.map((model) => model.name)
-      return filenames.sort()
+    try {
+      const listing = await this._contentsManager.get(path, { content: true })
+      if (listing.type == "file") {
+        return [listing.name]
+      } else {  // listing.type == "directory"
+        const content = listing.content as Contents.IModel[]
+        const filenames = content.map((model) => model.name)
+        return filenames.sort()
+      }
+    } catch (error: any) {
+      // Need to handle possible error cases here.
+      return []
     }
   }
 
@@ -34,5 +39,9 @@ export class JupyterFileSystem implements IFileSystem {
     await this._contentsManager.rename(model.path, path)
   }
 
+  async write(path: string, content: string): Promise<void> {
+    await this._contentsManager.save(path, { content })
+  }
+
   private _contentsManager: Contents.IManager
 }
diff --git a/src/shell.ts b/src/shell.ts
index ae11c65..a062098 100644
--- a/src/shell.ts
+++ b/src/shell.ts
@@ -1,6 +1,6 @@
 import { CommandRegistry } from "./command_registry"
 import { Context } from "./context"
-import { TerminalOutput } from "./io"
+import { FileOutput, Output, TerminalOutput } from "./io"
 import { OutputCallback } from "./output_callback"
 import { CommandNode, parse } from "./parse"
 import { IFileSystem } from "./file_system"
@@ -105,11 +105,25 @@ export class Shell {
           throw new Error(`Unknown command: '${cmdName}'`)
         }
 
+        let output: Output = stdout
+        if (cmd.redirects) {
+          // Support single redirect only, write (not append) to file.
+          if (cmd.redirects.length > 1) {
+            throw Error("Only implemented a single redirect per command")
+          }
+          if (cmd.redirects[0].token.value != ">") {
+            throw Error("Only implemented redirect write to file")
+          }
+
+          const path = cmd.redirects[0].target.value
+          output = new FileOutput(this._filesystem, path, false)
+        }
+
         const cmdArgs = cmd.suffix.map((token) => token.value)
-        const context = new Context(cmdArgs, this._filesystem, stdout, this._env)
-        //const exit_code = await command?.run(context)
+        const context = new Context(cmdArgs, this._filesystem, output, this._env)
+        //const exit_code = await command?.run(context)  // Do something with exit_code
         await command?.run(context)
-        await stdout.flush()
+        await output.flush()
       }
     } catch (error: any) {
       // Send result via output??????  With color.  Should be to stderr.
diff --git a/tests/shell.test.ts b/tests/shell.test.ts
index b67c818..4d29881 100644
--- a/tests/shell.test.ts
+++ b/tests/shell.test.ts
@@ -28,6 +28,25 @@ describe("Shell", () => {
       await shell._runCommands("env")
       expect(output.text).toEqual("PS1=\x1b[1;31mjs-shell:$\x1b[1;0m \r\nPWD=/\r\nCOLUMNS=0\r\nLINES=0\r\n")
     })
+
+    it("should echo to terminal", async () => {
+      const fs = await file_system_setup("jupyter")
+      const output = new MockTerminalOutput()
+      const shell = new Shell(fs, output.callback)
+      await shell._runCommands("echo sometext")
+      expect(output.text).toEqual("sometext\r\n")
+    })
+
+    it("should echo to file", async () => {
+      const fs = await file_system_setup("jupyter")
+      const output = new MockTerminalOutput()
+      const shell = new Shell(fs, output.callback)
+      expect(await fs.list("afile.txt")).toEqual([])
+      await shell._runCommands("echo sometext > afile.txt")
+      expect(await fs.list("afile.txt")).toEqual(["afile.txt"])
+      // Should this really have appended \r\n ???
+      expect(await fs.get("afile.txt")).toEqual("sometext\r\n")
+    })
   })
 
   describe("input", () => {