Support code completion for inline snippet render arguments

Argument completion suggestions should be offered
while rendering an inline snippet. This commit adds
this functionality by selecting and displaying
arguments defined in an inline snippets doc tag

Author: dejmedus

.changeset/eleven-melons-compete.md

@@ -0,0 +1,5 @@
+---
+'@shopify/theme-language-server-common': minor
+---
+
+Support code completion for inline snippet render arguments

packages/theme-language-server-common/src/completions/providers/RenderSnippetParameterCompletionProvider.spec.ts

@@ -87,4 +87,95 @@ describe('Module: RenderSnippetParameterCompletionProvider', async () => {
   it('does not provide completion options if the snippet does not exist', async () => {
     await expect(provider).to.complete(`{% render 'fake-snippet', █ %}`, []);
   });
+
+  describe('inline snippets', () => {
+    it('provide completion options', async () => {
+      const content = `
+      {% snippet example %}
+        {% doc %}
+          @param {string} title 
+          @param {number} count 
+          @param description 
+        {% enddoc %}
+        <div>{{ title }} - {{ count }}</div>
+      {% endsnippet %}
+
+      {% render example, █ %}
+    `;
+      await expect(provider).to.complete(content, ['title', 'count', 'description']);
+    });
+
+    it('provide completion options and exclude already specified params', async () => {
+      const content = `
+      {% snippet example %}
+        {% doc %}
+          @param {string} title
+          @param {number} count
+          @param {boolean} active
+        {% enddoc %}
+        <div>{{ title }}</div>
+      {% endsnippet %}
+
+      {% render example, title: 'foo', █ %}
+    `;
+      await expect(provider).to.complete(content, ['count', 'active']);
+    });
+
+    it('do not provide completion options if there is no doc tag', async () => {
+      const content = `
+      {% snippet example %}
+        <div>No doc block here</div>
+      {% endsnippet %}
+
+      {% render example, █ %}
+    `;
+      await expect(provider).to.complete(content, []);
+    });
+
+    it('do not provide completion options if the snippet does not exist', async () => {
+      const content = `
+      {% snippet example %}
+        {% doc %}
+          @param {string} title
+        {% enddoc %}
+      {% endsnippet %}
+
+      {% render nonexistent, █ %}
+    `;
+      await expect(provider).to.complete(content, []);
+    });
+
+    it('provide completion options from the doc tag in the current scope', async () => {
+      let content = `
+        {% snippet outer %}
+          {% doc %}
+            @param {string} outerParam
+          {% enddoc %}
+          {% snippet inner %}
+            {% doc %}
+              @param {string} innerParam
+            {% enddoc %}
+            <div>{{ innerParam }}</div>
+          {% endsnippet %}
+          {% render inner, █ %}
+        {% endsnippet %}
+      `;
+      await expect(provider).to.complete(content, ['innerParam']);
+      content = `
+        {% snippet outer %}
+          {% doc %}
+            @param {string} outerParam
+          {% enddoc %}
+          {% snippet inner %}
+            {% doc %}
+              @param {string} innerParam
+            {% enddoc %}
+            <div>{{ innerParam }}</div>
+          {% endsnippet %}
+        {% endsnippet %}
+        {% render outer, █ %}
+      `;
+      await expect(provider).to.complete(content, ['outerParam']);
+    });
+  });
 });

packages/theme-language-server-common/src/completions/providers/RenderSnippetParameterCompletionProvider.ts

@@ -1,4 +1,12 @@
-import { NodeTypes } from '@shopify/liquid-html-parser';
+import {
+  LiquidDocParamNode,
+  NodeTypes,
+  LiquidHtmlNode,
+  LiquidTag,
+  LiquidVariableLookup,
+  RenderMarkup,
+  LiquidRawTag,
+} from '@shopify/liquid-html-parser';
 import {
   CompletionItem,
   CompletionItemKind,
@@ -10,7 +18,7 @@ import {
 import { CURSOR, LiquidCompletionParams } from '../params';
 import { Provider } from './common';
 import { formatLiquidDocParameter, getParameterCompletionTemplate } from '../../utils/liquidDoc';
-import { GetDocDefinitionForURI } from '@shopify/theme-check-common';
+import { GetDocDefinitionForURI, LiquidDocParameter, visit } from '@shopify/theme-check-common';
 
 export type GetSnippetNamesForURI = (uri: string) => Promise<string[]>;
 
@@ -27,21 +35,25 @@ export class RenderSnippetParameterCompletionProvider implements Provider {
       !node ||
       !parentNode ||
       node.type !== NodeTypes.VariableLookup ||
-      parentNode.type !== NodeTypes.RenderMarkup ||
-      parentNode.snippet.type !== 'String'
+      parentNode.type !== NodeTypes.RenderMarkup
     ) {
       return [];
     }
 
     const userInputStr = node.name?.replace(CURSOR, '') || '';
+    let liquidDocParams;
 
-    const snippetDefinition = await this.getDocDefinitionForURI(
-      params.textDocument.uri,
-      'snippets',
-      parentNode.snippet.value,
-    );
+    if (parentNode.snippet.type === 'String') {
+      const snippetDefinition = await this.getDocDefinitionForURI(
+        params.textDocument.uri,
+        'snippets',
+        parentNode.snippet.value,
+      );
 
-    const liquidDocParams = snippetDefinition?.liquidDoc?.parameters;
+      liquidDocParams = snippetDefinition?.liquidDoc?.parameters;
+    } else if (parentNode.snippet.type === NodeTypes.VariableLookup) {
+      liquidDocParams = getInlineSnippetDocParams(params, parentNode);
+    }
 
     if (!liquidDocParams) {
       return [];
@@ -77,3 +89,48 @@ export class RenderSnippetParameterCompletionProvider implements Provider {
       });
   }
 }
+
+function getInlineSnippetDocParams(
+  params: LiquidCompletionParams,
+  parentNode: RenderMarkup,
+): LiquidDocParameter[] {
+  const ast = params.document.ast;
+  if (ast instanceof Error || ast.type !== NodeTypes.Document) return [];
+
+  const snippetName = (parentNode.snippet as LiquidVariableLookup).name;
+  let snippetNode: LiquidHtmlNode | undefined;
+
+  visit(ast, {
+    LiquidTag(node: LiquidTag) {
+      if (
+        node.name === 'snippet' &&
+        typeof node.markup !== 'string' &&
+        node.markup.type === NodeTypes.VariableLookup &&
+        node.markup.name === snippetName
+      ) {
+        snippetNode = node;
+      }
+    },
+  });
+
+  if (!snippetNode || !('children' in snippetNode)) return [];
+
+  const docNode = snippetNode.children?.find(
+    (node) => node.type === NodeTypes.LiquidRawTag && (node as LiquidRawTag).name === 'doc',
+  ) as LiquidRawTag | undefined;
+
+  if (!docNode) return [];
+
+  const bodyNodes = docNode.body.nodes as unknown as LiquidHtmlNode[];
+  const paramNodes = bodyNodes.filter(
+    (node): node is LiquidDocParamNode => node.type === NodeTypes.LiquidDocParamNode,
+  );
+
+  return paramNodes.map((node) => ({
+    nodeType: 'param',
+    name: node.paramName.value,
+    description: node.paramDescription?.value ?? null,
+    type: node.paramType?.value ?? null,
+    required: node.required,
+  })) as LiquidDocParameter[];
+}