added help message

paolo-projects · May 31, 2022 · 3659f1c · 3659f1c
1 parent 75c6373
commit 3659f1c
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Showing 3 changed files with 29 additions and 3 deletions.
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@paolo-projects/terminal-emulator",
-    "version": "0.2.0",
+    "version": "0.2.1",
     "description": "",
     "main": "build/index.js",
     "types": "build/index.d.ts",

diff --git a/src/CommandScheme/index.ts b/src/CommandScheme/index.ts
@@ -3,6 +3,7 @@ import FlagArgument from '../Argument/FlagArgument';
 import PositionalArgument from '../Argument/PositionalArgument';
 import ValueArgument from '../Argument/ValueArgument';
 import Command from '../Command';
+import OutputStream from '../OutputStream';
 import ArgumentScheme, {
     FlagArgumentScheme,
     PositionalArgumentScheme,
@@ -15,16 +16,24 @@ export type CommandSchemeMatchCallback = (
 ) => Promise<boolean>;
 
 export default class CommandScheme {
+    private outputStream?: OutputStream;
+
     private constructor(
         public name: string,
         public argSchemes: ArgumentScheme[],
-        public matchCallback: CommandSchemeMatchCallback
+        public matchCallback: CommandSchemeMatchCallback,
+        public helpMessage?: string
     ) {}
 
+    setOutputStream(stream: OutputStream) {
+        this.outputStream = stream;
+    }
+
     static Builder = class {
         name: string;
         args: ArgumentScheme[] = [];
         schemeCallback?: CommandSchemeMatchCallback;
+        helpMsg?: string;
 
         constructor(commandName: string) {
             this.name = commandName;
@@ -56,6 +65,11 @@ export default class CommandScheme {
             return this;
         }
 
+        withHelpMessage(helpMessage: string) {
+            this.helpMsg = helpMessage;
+            return this;
+        }
+
         callback(callback: CommandSchemeMatchCallback) {
             this.schemeCallback = callback;
             return this;
@@ -65,7 +79,8 @@ export default class CommandScheme {
             return new CommandScheme(
                 this.name,
                 this.args,
-                this.schemeCallback!!
+                this.schemeCallback!!,
+                this.helpMsg
             );
         }
     };
@@ -75,6 +90,16 @@ export default class CommandScheme {
             return false;
         }
 
+        if (
+            this.helpMessage &&
+            command.args.filter(
+                (arg) => arg instanceof FlagArgument && arg.name === 'help'
+            ).length
+        ) {
+            this.outputStream?.writeLine(this.helpMessage);
+            return true;
+        }
+
         for (const argScheme of this.argSchemes) {
             switch (argScheme.argType) {
                 case 'positional':

diff --git a/src/TerminalEmulator/index.ts b/src/TerminalEmulator/index.ts
@@ -17,6 +17,7 @@ export default class TerminalEmulator {
     private commandNotFoundHandler: CommandCallback | null = null;
 
     command(scheme: CommandScheme): TerminalEmulator {
+        scheme.setOutputStream(this.outputStream);
         this.commandSchemes.push(scheme);
         return this;
     }