feat(command): add values method to types to show possible values in…

… help text (#202)

command/command.ts

@@ -581,12 +581,17 @@ export class Command<
 
     this.cmd.types.set(name, { ...options, name, handler });
 
-    if (handler instanceof Type && typeof handler.complete !== "undefined") {
-      this.complete(
-        name,
-        (cmd, parent?: Command) => handler.complete?.(cmd, parent) || [],
-        options,
-      );
+    if (
+      handler instanceof Type &&
+      (typeof handler.complete !== "undefined" ||
+        typeof handler.values !== "undefined")
+    ) {
+      const completeHandler: ICompleteHandler = (
+        cmd: Command,
+        parent?: Command,
+      ) =>
+        handler.complete?.(cmd, parent) || handler.values?.(cmd, parent) || [];
+      this.complete(name, completeHandler, options);
     }
 
     return this;
@@ -1703,23 +1708,23 @@ export class Command<
    * Get type by name.
    * @param name Name of the type.
    */
-  protected getType(name: string): IType | undefined {
+  public getType(name: string): IType | undefined {
     return this.getBaseType(name) ?? this.getGlobalType(name);
   }
 
   /**
    * Get base type by name.
    * @param name Name of the type.
    */
-  protected getBaseType(name: string): IType | undefined {
+  public getBaseType(name: string): IType | undefined {
     return this.types.get(name);
   }
 
   /**
    * Get global type by name.
    * @param name Name of the type.
    */
-  protected getGlobalType(name: string): IType | undefined {
+  public getGlobalType(name: string): IType | undefined {
     if (!this._parent) {
       return;
     }

command/help/_help_generator.ts

@@ -14,6 +14,7 @@ import {
 } from "../deps.ts";
 import type { IArgument } from "../types.ts";
 import type { IEnvVar, IExample, IOption } from "../types.ts";
+import { Type } from "../type.ts";
 
 export interface HelpOptions {
   types?: boolean;
@@ -238,15 +239,25 @@ export class HelpGenerator {
       red(bold(`Conflicts: `)) +
         italic(option.conflicts.map(getFlag).join(", ")),
     );
-    (Array.isArray(option.value) || option.value instanceof RegExp) &&
+
+    let possibleValues: Array<string | number | RegExp> | undefined;
+    if (option.value instanceof RegExp) {
+      possibleValues = [option.value];
+    } else if (Array.isArray(option.value)) {
+      possibleValues = option.value;
+    } else {
+      const type = this.cmd.getType(option.args[0]?.type)?.handler;
+      if (type instanceof Type) {
+        possibleValues = type.values?.(this.cmd, this.cmd.getParent());
+      }
+    }
+
+    if (possibleValues) {
       hints.push(
-        bold(`Possible values: `) +
-          italic(
-            (Array.isArray(option.value)
-              ? option.value
-              : [option.value.toString()]).join(", "),
-          ),
+        bold(`Values: `) +
+          possibleValues.map((value: unknown) => inspect(value)).join(", "),
       );
+    }
 
     if (hints.length) {
       return `(${hints.join(", ")})`;

command/test/integration/fixtures/help_command.out

@@ -8,11 +8,11 @@
 
   Options:
 
-    -h, --help            - Show this help.                            
-    -V, --version         - Show the version number for this program.  
-    -g, --global   <val>  - Foo option.                                
-    -m, --main     <val>  - Bar option.                                
-    -c, --color    <val>  - Color option.                              
+    -h, --help            - Show this help.                                                             
+    -V, --version         - Show the version number for this program.                                   
+    -g, --global   <val>  - Foo option.                                                                 
+    -m, --main     <val>  - Bar option.                                                                 
+    -c, --color    <val>  - Color option.                              (Values: "blue", "yellow", "red")
 
   Commands:
 

command/test/integration/fixtures/help_option_long.out

@@ -8,11 +8,11 @@
 
   Options:
 
-    -h, --help            - Show this help.                            
-    -V, --version         - Show the version number for this program.  
-    -g, --global   <val>  - Foo option.                                
-    -m, --main     <val>  - Bar option.                                
-    -c, --color    <val>  - Color option.                              
+    -h, --help            - Show this help.                                                             
+    -V, --version         - Show the version number for this program.                                   
+    -g, --global   <val>  - Foo option.                                                                 
+    -m, --main     <val>  - Bar option.                                                                 
+    -c, --color    <val>  - Color option.                              (Values: "blue", "yellow", "red")
 
   Commands:
 

command/test/integration/fixtures/help_option_short.out

@@ -8,11 +8,11 @@
 
   Options:
 
-    -h, --help            - Show this help.                            
-    -V, --version         - Show the version number for this program.  
-    -g, --global   <val>  - Foo option.                                
-    -m, --main     <val>  - Bar option.                                
-    -c, --color    <val>  - Color option.                              
+    -h, --help            - Show this help.                                                             
+    -V, --version         - Show the version number for this program.                                   
+    -g, --global   <val>  - Foo option.                                                                 
+    -m, --main     <val>  - Bar option.                                                                 
+    -c, --color    <val>  - Color option.                              (Values: "blue", "yellow", "red")
 
   Commands:
 

command/test/integration/test.ts

@@ -1,4 +1,4 @@
-import { assertEquals, dirname, expandGlob } from "../../../dev_deps.ts";
+import { assertEquals, dirname, expandGlob, lt } from "../../../dev_deps.ts";
 
 const baseDir = `${dirname(import.meta.url).replace("file://", "")}`;
 
@@ -8,7 +8,7 @@ for await (const file of expandGlob(`${baseDir}/fixtures/*.in`)) {
     const outPath = file.path.replace(/\.in$/, ".out");
     Deno.test({
       name: `command - integration - ${name}`,
-      ignore: Deno.build.os === "windows",
+      ignore: Deno.build.os === "windows" || lt(Deno.version.deno, "1.4.1"),
       async fn() {
         const [cmd, expected] = await Promise.all([
           Deno.readTextFile(file.path),

command/type.ts

@@ -1,5 +1,9 @@
 import type { Command } from "./command.ts";
-import type { CompleteHandlerResult, ITypeInfo } from "./types.ts";
+import type {
+  CompleteHandlerResult,
+  ITypeInfo,
+  ValuesHandlerResult,
+} from "./types.ts";
 
 /**
  * Base class for custom types.
@@ -26,6 +30,21 @@ import type { CompleteHandlerResult, ITypeInfo } from "./types.ts";
 export abstract class Type<T> {
   public abstract parse(type: ITypeInfo): T;
 
+  /**
+   * Returns values displayed in help text. If no complete method is provided,
+   * these values are also used for shell completions.
+   */
+  public values?(
+    // deno-lint-ignore no-explicit-any
+    cmd: Command<any, any, any, any, any>,
+    // deno-lint-ignore no-explicit-any
+    parent?: Command<any, any, any, any, any>,
+  ): ValuesHandlerResult;
+
+  /**
+   * Returns shell completion values. If no complete method is provided,
+   * values from the values method are used.
+   */
   public complete?(
     // deno-lint-ignore no-explicit-any
     cmd: Command<any, any, any, any, any>,

command/types.ts

@@ -194,6 +194,8 @@ export type CompleteHandlerResult =
   | Array<string | number>
   | Promise<Array<string | number>>;
 
+export type ValuesHandlerResult = Array<string | number>;
+
 /** Type parser method. */
 export type ICompleteHandler<
   // deno-lint-ignore no-explicit-any

command/types/enum.ts

@@ -21,7 +21,7 @@ export class EnumType<T extends string | number> extends Type<T> {
     throw new InvalidTypeError(type, this.allowedValues.slice());
   }
 
-  public complete(): T[] {
+  public values(): T[] {
     return this.allowedValues.slice();
   }
 }