fix(cli): better command line helper text content and format

Summary:
## Before
 {F1968819378}

## After
 {F1968819329}

Differential Revision: D66548359

fbshipit-source-id: b54289477f782dd64e003e3e7a808f6281f18728

packages/cli/src/commands/helper/HelperCommand.ts

@@ -220,8 +220,8 @@ export default class HelperCommand extends BaseCommand {
     const cmd = docUtils.generateExampleCommand(name, example, {
       descriptionAsBashComment: false,
     });
-    let msg = `${indent}${cmd}`;
-    msg += `\n${indent}${desc}`;
+    let msg = docUtils.indentText(cmd, indent);
+    msg += `\n${docUtils.indentText(desc, indent)}`;
 
     if (options.printOptions && cmdDoc.length > 0) {
       const cmdDocBlock = alignTextInBlock(cmdDoc, {

packages/cli/src/commands/helper/lib/DocUtils.ts

@@ -54,6 +54,72 @@ function exampleFromCliOptionString(
   return `memlab ${command} ${cliExample.trim()}`;
 }
 
+function getCLIWidth() {
+  return process.stdout.columns || 80; // Default to 80 if undefined
+}
+
+function indentText(description: string, indent: string): string {
+  const cliWidth = getCLIWidth();
+  const availableWidth = cliWidth - indent.length;
+  const lines: Array<string> = [];
+
+  // Split the description by \n to handle existing line breaks
+  const descriptionLines = description.split('\n');
+
+  descriptionLines.forEach(descLine => {
+    const words = descLine.split(/\s+/);
+    let line = '';
+    for (let i = 0; i < words.length; i++) {
+      const word = words[i];
+      if (line.length === 0) {
+        // Start a new line with the word
+        if (word.length > availableWidth) {
+          // The word itself is longer than the available width
+          // Split the word
+          let start = 0;
+          while (start < word.length) {
+            const part = word.substring(start, start + availableWidth);
+            lines.push(indent + part);
+            start += availableWidth;
+          }
+          line = '';
+        } else {
+          line = word;
+        }
+      } else {
+        const potentialLine = line + ' ' + word;
+        if (potentialLine.length <= availableWidth) {
+          line = potentialLine;
+        } else {
+          // Line is full, push it and start new line
+          lines.push(indent + line);
+          if (word.length > availableWidth) {
+            // The word itself is longer than the available width
+            // Split the word
+            let start = 0;
+            while (start < word.length) {
+              const part = word.substring(start, start + availableWidth);
+              lines.push(indent + part);
+              start += availableWidth;
+            }
+            line = '';
+          } else {
+            line = word;
+          }
+        }
+      }
+    }
+    // Push the last line if any
+    if (line.length > 0) {
+      lines.push(indent + line);
+    }
+  });
+
+  // Join all lines with \n
+  return lines.join('\n');
+}
+
 export default {
+  indentText,
   generateExampleCommand,
 };

packages/heap-analysis/src/options/HeapAnalysisOutputOption.ts

@@ -18,7 +18,13 @@ export default class HeapAnalysisOutputOption extends BaseOption {
   }
 
   getDescription(): string {
-    return 'specify output format of the analysis (defaults to text)';
+    const options = this.getExampleValues()
+      .map(v => `'${v}'`)
+      .join(', ');
+    return (
+      'specify output format of the analysis ' +
+      `(available options: ${options}; defaults to 'text')`
+    );
   }
 
   getExampleValues(): string[] {

website/docs/cli/CLI-commands.md

@@ -215,7 +215,7 @@ memlab analyze collections-with-stale
 
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode
@@ -232,7 +232,7 @@ memlab analyze detached-DOM
 
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode
@@ -249,7 +249,7 @@ memlab analyze global-variable
 
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode
@@ -267,7 +267,7 @@ memlab analyze object
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
  * **`--node-id`**: set heap node ID
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode
@@ -284,7 +284,7 @@ memlab analyze object-fanout
 
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode
@@ -333,7 +333,7 @@ memlab analyze object-size
 
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode
@@ -414,7 +414,7 @@ memlab analyze unmounted-fiber-node
 
 **Options**:
  * **`--snapshot`**: set file path of the heap snapshot under analysis
- * **`--output`**: specify output format of the analysis (defaults to text)
+ * **`--output`**: specify output format of the analysis (available options: 'text', 'json'; defaults to 'text')
  * **`--help`**, **`-h`**: print helper text
  * **`--verbose`**, **`-v`**: show more details
  * **`--sc`**: set to continuous test mode