feat: consolidate comments from nested levels of schemas

DX-592

packages/openapi-generator/src/comments.ts

@@ -1,4 +1,5 @@
 import { parse as parseComment, Block } from 'comment-parser';
+import { Schema } from './ir';
 
 export function leadingComment(
   src: string,
@@ -42,3 +43,69 @@ export function leadingComment(
   const parsedComment = parseComment(commentString);
   return parsedComment;
 }
+
+/**
+ *
+ * @param schema the schema to get all comments from
+ * @returns an array of all comments in the schema
+ */
+export function getAllSchemaComments(schema: Schema): Block[] {
+  const result = [];
+
+  /** Push the first comment */
+  if (schema.comment) {
+    result.push(schema.comment);
+  }
+
+  /** Push the comments of the subschemas in CombinedTypes (union, intersection, etc) */
+  if ('schemas' in schema) {
+    // combined type
+    for (const s of schema.schemas) {
+      result.push(...getAllSchemaComments(s));
+    }
+  }
+
+  return result;
+}
+
+/**
+ *
+ * @param schema the schema to combine comments from
+ * @returns a combined comment from all comments in the schema
+ */
+export function combineComments(schema: Schema): Block | undefined {
+  const comments = getAllSchemaComments(schema);
+
+  const tagSet = new Set<string>();
+
+  // Empty comment block where we will build the result
+  const result: Block = {
+    tags: [],
+    description: '',
+    problems: [],
+    source: [],
+  };
+
+  if (comments.length === 0) return undefined;
+
+  // Only use the first description if it exists, we don't wanna accidentally pull a description from a lower level schema
+  if (comments[0]?.description && comments[0].description !== '') {
+    result.description = comments[0].description;
+  }
+
+  // Add all seen tags, problems, and source comments to the result
+  for (const comment of comments) {
+    for (const tag of comment.tags) {
+      // Only add the tag if we haven't seen it before. Otherwise, the higher level tag is 'probably' the more relevant tag.
+      if (!tagSet.has(tag.tag)) {
+        result.tags.push(tag);
+        tagSet.add(tag.tag);
+      }
+    }
+
+    result.problems.push(...comment.problems);
+    result.source.push(...comment.source);
+  }
+
+  return result;
+}

packages/openapi-generator/src/optimize.ts

@@ -1,3 +1,4 @@
+import { combineComments } from './comments';
 import { isPrimitive, type Primitive, type Schema } from './ir';
 
 export type OptimizeFn = (schema: Schema) => Schema;
@@ -173,6 +174,15 @@ export function filterUndefinedUnion(schema: Schema): [boolean, Schema] {
   }
 }
 
+// This function is a helper that adds back any comments that were removed during optimization
+function withComment(newSchema: Schema, oldSchema: Schema): Schema {
+  if (oldSchema.comment) {
+    newSchema.comment = combineComments(oldSchema);
+  }
+
+  return newSchema;
+}
+
 export function optimize(schema: Schema): Schema {
   if (schema.type === 'object') {
     const properties: Record<string, Schema> = {};
@@ -184,8 +194,8 @@ export function optimize(schema: Schema): Schema {
       }
       const [isOptional, filteredSchema] = filterUndefinedUnion(optimized);
 
-      if (prop.comment) {
-        filteredSchema.comment = prop.comment;
+      if (optimized.comment) {
+        filteredSchema.comment = optimized.comment;
       }
 
       properties[key] = filteredSchema;
@@ -197,50 +207,27 @@ export function optimize(schema: Schema): Schema {
 
     const schemaObject: Schema = { type: 'object', properties, required };
 
-    // only add comment field if there is a comment
-    if (schema.comment) {
-      return { ...schemaObject, comment: schema.comment };
-    }
-
-    return schemaObject;
+    return withComment(schemaObject, schema);
   } else if (schema.type === 'intersection') {
     const newSchema = foldIntersection(schema, optimize);
-    if (schema.comment) {
-      return { ...newSchema, comment: schema.comment };
-    }
-    return newSchema;
+
+    return withComment(newSchema, schema);
   } else if (schema.type === 'union') {
     const consolidated = consolidateUnion(schema);
     const simplified = simplifyUnion(consolidated, optimize);
     const merged = mergeUnions(simplified);
 
-    if (schema.comment) {
-      return { ...merged, comment: schema.comment };
-    }
-
-    return merged;
+    return withComment(merged, schema);
   } else if (schema.type === 'array') {
     const optimized = optimize(schema.items);
-    if (schema.comment) {
-      return { type: 'array', items: optimized, comment: schema.comment };
-    }
-    return { type: 'array', items: optimized };
+
+    return withComment({ type: 'array', items: optimized }, schema);
   } else if (schema.type === 'record') {
-    if (schema.comment) {
-      return {
-        type: 'record',
-        codomain: optimize(schema.codomain),
-        comment: schema.comment,
-      };
-    }
-    return { type: 'record', codomain: optimize(schema.codomain) };
+    return withComment({ type: 'record', codomain: optimize(schema.codomain) }, schema);
   } else if (schema.type === 'tuple') {
     const schemas = schema.schemas.map(optimize);
-    return { type: 'tuple', schemas };
+    return withComment({ type: 'tuple', schemas }, schema);
   } else if (schema.type === 'ref') {
-    if (schema.comment) {
-      return { ...schema, comment: schema.comment };
-    }
     return schema;
   } else {
     return schema;