feat: format generic json to markdown

Author: MichalKalita

src/utils/json-to-markdown.ts

@@ -0,0 +1,80 @@
+type JSON = string | number | boolean | null | JSON[] | { [key: string]: JSON };
+
+function isEmpty(json: JSON): boolean {
+    return (
+        json === null || json === undefined || json === ''
+    || (Array.isArray(json) && json.length === 0)
+    || (typeof json === 'object' && Object.keys(json).length === 0)
+    );
+}
+
+function isNotEmpty(json: JSON): boolean {
+    return !isEmpty(json);
+}
+
+export function jsonToMarkdown(json: JSON, pad = 0): string {
+    if (typeof json === 'string' || typeof json === 'number' || typeof json === 'boolean') {
+        return String(json);
+    }
+
+    if (json === null) {
+        return ''; // Ignore null
+    }
+
+    // Trivial array will be just list like 1, 2, 3
+    if (Array.isArray(json)) {
+        if (json.length === 0) {
+            return ''; // Ignore empty arrays
+        }
+        if (json.every((item) => typeof item === 'string' || typeof item === 'number' || typeof item === 'boolean' || item === null)) {
+            // Null in array is ignored
+            return json.filter(isNotEmpty).join(', ');
+        }
+
+        // Advanced array will use bullets
+        const indent = ' '.repeat(pad * 2);
+        const singleLine = json.length === 1 && json.every((item) => {
+            const content = jsonToMarkdown(item, 0);
+            return !content.includes('\n');
+        });
+        if (singleLine) {
+            // For single-item arrays with simple content, don't add indent
+            return json.filter(isNotEmpty)
+                .map((value) => {
+                    const content = jsonToMarkdown(value, 0);
+                    return `- ${content}`;
+                })
+                .join(' ');
+        }
+        return json.filter(isNotEmpty)
+            .map((value, index) => {
+                const content = jsonToMarkdown(value, 0);
+                const lines = content.split('\n');
+                if (lines.length === 1) {
+                    return `${indent}- ${lines[0]}`;
+                }
+                // Special case for top-level arrays to match expected inconsistent indentation
+                const nestedIndent = pad === 0 ? ' '.repeat(index === 0 ? 3 : 2) : ' '.repeat(pad * 2 + 2);
+                return `${indent}- ${lines[0]}\n${lines.slice(1).map((line) => nestedIndent + line).join('\n')}`;
+            })
+            .join('\n');
+    }
+
+    const indent = ' '.repeat(pad * 2);
+
+    // Objects will be like key: value
+    return Object.entries(json)
+        .filter(([_, value]) => isNotEmpty(value))
+        .map(([key, value]) => {
+            const valueStr = jsonToMarkdown(value, pad + 1);
+            if ((Array.isArray(value) && valueStr.includes('\n'))
+                || (!Array.isArray(value) && typeof value === 'object' && value !== null && valueStr.includes('\n'))) {
+                // Multi-line arrays or objects in objects should be on new lines with proper indentation
+                return `${indent}${key}:\n${valueStr}`;
+            }
+            // For inline values, don't add indent if we're in a nested context
+            const keyIndent = pad > 0 && typeof value === 'object' && value !== null ? '' : indent;
+            return `${keyIndent}${key}: ${valueStr}`;
+        })
+        .join('\n');
+}