From a9cdde0a6db374e13fd882d6b072ae68c666043a Mon Sep 17 00:00:00 2001
From: Alberto Marchetti <cmaster11@gmail.com>
Date: Sun, 17 Dec 2023 08:32:52 +0200
Subject: [PATCH] Support description/example indentation

---
 src/__tests__/description/index.ts            | 18 +++++++-
 .../description/schemas/OneSchema.ts          | 27 ++++++++---
 src/write.ts                                  | 46 +++++++++++++++++--
 3 files changed, 77 insertions(+), 14 deletions(-)

diff --git a/src/__tests__/description/index.ts b/src/__tests__/description/index.ts
index 9cf3ac03..fe341e47 100644
--- a/src/__tests__/description/index.ts
+++ b/src/__tests__/description/index.ts
@@ -114,16 +114,30 @@ export interface Example {
 }
 
 /**
- * This is a long description.
+ * This is a long indented description.
  * There are many lines!
  *
  * And more here!
  */
 export interface ExampleLong {
   /**
-   * another
+   * Another description
    */
   another: string;
+  /**
+   * Not indented description
+   */
+  noIndent?: string;
+  /**
+   * Badly indented description
+   *     What a line
+   */
+  badIndent?: string;
+  /**
+   * Another badly indented description
+   *   What a line
+   */
+  badIndent2?: string;
 }
 
 /**
diff --git a/src/__tests__/description/schemas/OneSchema.ts b/src/__tests__/description/schemas/OneSchema.ts
index 6425a507..d5a00e56 100644
--- a/src/__tests__/description/schemas/OneSchema.ts
+++ b/src/__tests__/description/schemas/OneSchema.ts
@@ -7,12 +7,25 @@ export const exampleSchema = Joi.object({
   .description('A simple description');
 
 export const exampleLongSchema = Joi.object({
-  another: Joi.string().required()
+  another: Joi.string().required().description(`
+  Another description
+  `),
+  noIndent: Joi.string().description(`
+Not indented description
+`),
+  badIndent: Joi.string().description(`
+Badly indented description
+    What a line
+`),
+  badIndent2: Joi.string().description(`
+    Another badly indented description
+  What a line
+`)
 }).meta({ className: 'ExampleLong' }).description(`
-This is a long description.
-There are many lines!
+  This is a long indented description.
+  There are many lines!
 
-And more here!
+  And more here!
 `);
 
 export const noCommentSchema = Joi.object({
@@ -51,9 +64,9 @@ export const exampleNewLineSchema = Joi.object({
 })
   .example(
     `
-I have many
-lines!
-`
+  I have many
+  lines!
+  `
   )
   .meta({ className: 'ExampleNewLine' });
 
diff --git a/src/write.ts b/src/write.ts
index 964f9485..6833adb0 100644
--- a/src/write.ts
+++ b/src/write.ts
@@ -56,7 +56,7 @@ export function getJsDocString(settings: Settings, name: string, jsDoc?: JsDoc,
   if (settings.commentEverything || (jsDoc && jsDoc.description)) {
     let description = name;
     if (jsDoc?.description) {
-      description = jsDoc.description.trim();
+      description = getStringIndentation(jsDoc.description).deIndentedString;
     }
     lines.push(...description.split('\n').map(line => ` * ${line}`.trimEnd()));
   }
@@ -67,13 +67,13 @@ export function getJsDocString(settings: Settings, name: string, jsDoc?: JsDoc,
   }
 
   for (const example of jsDoc?.examples ?? []) {
-    const trimmed = example.trim();
+    const deIndented = getStringIndentation(example).deIndentedString;
 
-    if (trimmed.includes('\n')) {
+    if (deIndented.includes('\n')) {
       lines.push(` * @example`);
-      lines.push(...trimmed.split('\n').map(line => ` * ${line}`.trimEnd()));
+      lines.push(...deIndented.split('\n').map(line => ` * ${line}`.trimEnd()));
     } else {
-      lines.push(` * @example ${trimmed}`);
+      lines.push(` * @example ${deIndented}`);
     }
   }
 
@@ -83,3 +83,39 @@ export function getJsDocString(settings: Settings, name: string, jsDoc?: JsDoc,
 
   return lines.map(line => `${getIndentStr(settings, indentLevel)}${line}`).join('\n') + '\n';
 }
+
+interface GetStringIndentationResult {
+  deIndentedString: string;
+  indent: string;
+}
+
+/**
+ * Given an indented string, uses the first line's indentation as base to de-indent
+ * the rest of the string, and returns both the de-indented string and the
+ * indentation found as prefix.
+ */
+function getStringIndentation(value: string): GetStringIndentationResult {
+  const lines = value.split('\n');
+  let indent = '';
+  for (const line of lines) {
+    // Skip initial newlines
+    if (line.trim() == '') {
+      continue;
+    }
+    const match = /^(\s+)\b/.exec(line);
+    if (match) {
+      indent = match[1];
+    }
+    break;
+  }
+
+  const deIndentedString = lines
+    .map(line => (line.startsWith(indent) ? line.substring(indent.length) : line))
+    .join('\n')
+    .trim();
+
+  return {
+    deIndentedString,
+    indent
+  };
+}