Add /dev/null

Fixes #71.

package.json

@@ -1,6 +1,6 @@
 {
     "name": "fwdekker.com",
-    "version": "1.9.7",
+    "version": "1.10.0",
     "description": "The source code of [my personal website](https://fwdekker.com/).",
     "author": "Felix W. Dekker",
     "repository": {

src/main/js/Commands.ts

@@ -527,7 +527,7 @@ export class Commands {
             return -1;
         }
 
-        window.open(node.contents, target);
+        window.open(node.open("read").read(), target);
         return 0;
     }
 

src/main/js/FileSystem.ts

@@ -21,6 +21,9 @@ export class FileSystem {
         if (root === undefined)
             this.root =
                 new Directory({
+                    "dev": new Directory({
+                        "null": new NullFile()
+                    }),
                     "home": new Directory({
                         "felix": new Directory({
                             "personal": new Directory({
@@ -551,18 +554,28 @@ export class File extends Node {
     protected type: string = "File";
 
     /**
-     * The link to the external resource.
+     * The contents of this file. !!Do not use this field directly!!
      */
-    contents: string;
+    _contents: string;
 
 
     /**
      * Constructs a new file.
+     *
+     * @param contents the contents of this file
      */
     constructor(contents: string = "") {
         super();
 
-        this.contents = contents;
+        this._contents = contents;
+    }
+
+
+    /**
+     * Returns the contents of this file.
+     */
+    get contents(): string {
+        return this._contents;
     }
 
 
@@ -578,7 +591,7 @@ export class File extends Node {
             case "read":
                 return new FileStream(this, 0);
             case "write":
-                this.contents = "";
+                this._contents = "";
                 return new FileStream(this, 0);
         }
     }
@@ -623,6 +636,28 @@ export class File extends Node {
     }
 }
 
+/**
+ * A file that cannot have contents.
+ */
+export class NullFile extends File {
+    open(mode: "append" | "read" | "write"): FileStream {
+        return new class extends FileStream {
+            constructor(file: File, pointer: number) {
+                super(file, pointer);
+            }
+
+
+            read(count: number | undefined = undefined): string {
+                return "";
+            }
+
+            write(string: string): void {
+                // Do nothing
+            }
+        }(this, 0);
+    }
+}
+
 
 /**
  * The mode to open a file in.
@@ -671,6 +706,6 @@ export class FileStream extends Stream {
         const pre = this.file.contents.slice(0, this.pointer);
         const post = this.buffer.slice(string.length);
 
-        this.file.contents = pre + string + post;
+        this.file._contents = pre + string + post;
     }
 }

src/test/Directory.spec.ts

@@ -130,8 +130,8 @@ describe("directory", () => {
             });
             const copy = directory.copy();
 
-            (<File>directory.getNode("file")).contents = "changed";
-            expect((<File>copy.getNode("file")).contents).to.equal("contents");
+            (<File>directory.getNode("file")).open("write").write("changed");
+            expect((<File>copy.getNode("file")).open("read").read()).to.equal("contents");
 
             (<Directory>directory.getNode("dir")).addNode("file2", new File());
             expect((<Directory>copy.getNode("dir")).nodeCount).to.equal(0);

src/test/File.spec.ts

@@ -1,7 +1,7 @@
 import "mocha";
 import {expect} from "chai";
 
-import {File} from "../main/js/FileSystem";
+import {File, NullFile} from "../main/js/FileSystem";
 
 
 describe("file", () => {
@@ -45,3 +45,27 @@ describe("file", () => {
         });
     });
 });
+
+describe("null file", () => {
+    let file: NullFile;
+
+
+    beforeEach(() => {
+        file = new NullFile();
+    });
+
+
+    it("has empty contents", () => {
+        expect(file.contents).to.equal("");
+    });
+
+    it("is empty after writing to it", () => {
+        file.open("write").write("contents");
+
+        expect(file.contents).to.equal("");
+    });
+
+    it("is empty when reading from a stream", () => {
+        expect(file.open("read").read()).to.equal("");
+    });
+});

src/test/FileSystem.spec.ts

@@ -121,9 +121,9 @@ describe("file system", () => {
             fileSystem.add(new Path("/src"), file, false);
 
             fileSystem.copy(new Path("/src"), new Path("/dst"), false);
-            file.contents = "new";
+            file.open("write").write("new");
 
-            expect((<File>fileSystem.get(new Path("/dst"))).contents).to.equal("old");
+            expect((<File>fileSystem.get(new Path("/dst"))).open("read").read()).to.equal("old");
         });
     });
 
@@ -205,9 +205,9 @@ describe("file system", () => {
             fileSystem.add(new Path("/src"), file, false);
 
             fileSystem.move(new Path("/src"), new Path("/dst"));
-            file.contents = "new";
+            file.open("write").write("new");
 
-            expect((<File>fileSystem.get(new Path("/dst"))).contents).to.equal("new");
+            expect((<File>fileSystem.get(new Path("/dst"))).open("read").read()).to.equal("new");
         });
 
         it("throws an error if the destination already exists", () => {