Parser: Detect image_tag Action View helper

Author: marcoroth

javascript/packages/language-server/src/action_view_helpers.ts

@@ -28,4 +28,8 @@ export const ACTION_VIEW_HELPERS: Record<string, ActionViewHelperInfo> = {
     signature: "javascript_include_tag(*sources)",
     documentationURL: "https://api.rubyonrails.org/classes/ActionView/Helpers/AssetTagHelper.html#method-i-javascript_include_tag",
   },
+  "ActionView::Helpers::AssetTagHelper#image_tag": {
+    signature: "image_tag(source, options = {})",
+    documentationURL: "https://api.rubyonrails.org/classes/ActionView/Helpers/AssetTagHelper.html#method-i-image_tag",
+  },
 }

javascript/packages/language-server/src/rewrite_code_action_service.ts

@@ -137,14 +137,17 @@ export class RewriteCodeActionService {
     const tagName = element.node.tag_name?.value
     const isAnchor = tagName === "a"
     const isTurboFrame = tagName === "turbo-frame"
+    const isImg = tagName === "img"
     const methodName = tagName?.replace(/-/g, "_")
     const title = isAnchor
       ? "Herb: Convert to `link_to`"
       : isTurboFrame
         ? "Herb: Convert to `turbo_frame_tag`"
-        : methodName
-          ? `Herb: Convert to \`tag.${methodName}\``
-          : "Herb: Convert to tag helper"
+        : isImg
+          ? "Herb: Convert to `image_tag`"
+          : methodName
+            ? `Herb: Convert to \`tag.${methodName}\``
+            : "Herb: Convert to tag helper"
 
     return {
       title,

javascript/packages/node/binding.gyp

@@ -26,6 +26,7 @@
         "./extension/libherb/analyze/transform.c",
         "./extension/libherb/analyze/action_view/attribute_extraction_helpers.c",
         "./extension/libherb/analyze/action_view/content_tag.c",
+        "./extension/libherb/analyze/action_view/image_tag.c",
         "./extension/libherb/analyze/action_view/javascript_include_tag.c",
         "./extension/libherb/analyze/action_view/javascript_tag.c",
         "./extension/libherb/analyze/action_view/link_to.c",

javascript/packages/rewriter/test/html-to-action-view-tag-helper.test.ts

@@ -184,7 +184,7 @@ describe("HTMLToActionViewTagHelperRewriter", () => {
 
     test("img with attributes", () => {
       expect(transform('<img src="image.png" alt="Photo">')).toBe(
-        '<%= tag.img src: "image.png", alt: "Photo" %>'
+        '<%= image_tag "image.png", alt: "Photo" %>'
       )
     })
   })
@@ -425,6 +425,44 @@ describe("HTMLToActionViewTagHelperRewriter", () => {
     })
   })
 
+  describe("image_tag for img elements", () => {
+    test("img with src attribute", () => {
+      expect(transform('<img src="icon.png">')).toBe(
+        '<%= image_tag "icon.png" %>'
+      )
+    })
+
+    test("img with src and alt", () => {
+      expect(transform('<img src="icon.png" alt="Icon">')).toBe(
+        '<%= image_tag "icon.png", alt: "Icon" %>'
+      )
+    })
+
+    test("img with src, alt and class", () => {
+      expect(transform('<img src="photo.jpg" alt="Photo" class="avatar">')).toBe(
+        '<%= image_tag "photo.jpg", alt: "Photo", class: "avatar" %>'
+      )
+    })
+
+    test("img with src and data attributes", () => {
+      expect(transform('<img src="icon.png" data-controller="image">')).toBe(
+        '<%= image_tag "icon.png", data: { controller: "image" } %>'
+      )
+    })
+
+    test("img self-closing", () => {
+      expect(transform('<img src="icon.png" />')).toBe(
+        '<%= image_tag "icon.png" %>'
+      )
+    })
+
+    test("img without src", () => {
+      expect(transform('<img alt="Photo">')).toBe(
+        '<%= image_tag alt: "Photo" %>'
+      )
+    })
+  })
+
   describe("ERB in attribute values", () => {
     test("single ERB expression becomes Ruby variable", () => {
       expect(transform('<div class="<%= class_name %>">Content</div>')).toBe(

src/analyze/action_view/image_tag.c

@@ -0,0 +1,79 @@
+#include <prism.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../../include/analyze/action_view/tag_helper_handler.h"
+
+bool detect_image_tag(pm_call_node_t* call_node, pm_parser_t* parser) {
+  if (!call_node || !call_node->name) { return false; }
+
+  pm_constant_t* constant = pm_constant_pool_id_to_constant(&parser->constant_pool, call_node->name);
+  return constant && constant->length == 9 && strncmp((const char*) constant->start, "image_tag", 9) == 0;
+}
+
+char* extract_image_tag_name(pm_call_node_t* _call_node, pm_parser_t* _parser, hb_allocator_T* allocator) {
+  return hb_allocator_strdup(allocator, "img");
+}
+
+char* extract_image_tag_content(pm_call_node_t* _call_node, pm_parser_t* _parser, hb_allocator_T* _allocator) {
+  return NULL;
+}
+
+char* extract_image_tag_src(pm_call_node_t* call_node, pm_parser_t* _parser, hb_allocator_T* allocator) {
+  if (!call_node || !call_node->arguments) { return NULL; }
+
+  pm_arguments_node_t* arguments = call_node->arguments;
+  if (!arguments->arguments.size) { return NULL; }
+
+  pm_node_t* first_argument = arguments->arguments.nodes[0];
+
+  if (first_argument->type == PM_STRING_NODE) {
+    pm_string_node_t* string_node = (pm_string_node_t*) first_argument;
+    size_t length = pm_string_length(&string_node->unescaped);
+
+    return hb_allocator_strndup(allocator, (const char*) pm_string_source(&string_node->unescaped), length);
+  }
+
+  size_t source_length = first_argument->location.end - first_argument->location.start;
+  return hb_allocator_strndup(allocator, (const char*) first_argument->location.start, source_length);
+}
+
+bool image_tag_source_is_url(const char* source, size_t length) {
+  if (!source || length == 0) { return false; }
+
+  if (length >= 2 && source[0] == '/' && source[1] == '/') { return true; }
+  if (strstr(source, "://") != NULL) { return true; }
+
+  return false;
+}
+
+char* wrap_in_image_path(const char* source, size_t source_length, hb_allocator_T* allocator) {
+  const char* prefix = "image_path(";
+  const char* suffix = ")";
+
+  size_t prefix_length = strlen(prefix);
+  size_t suffix_length = strlen(suffix);
+  size_t total_length = prefix_length + source_length + suffix_length;
+  char* result = hb_allocator_alloc(allocator, total_length + 1);
+
+  memcpy(result, prefix, prefix_length);
+  memcpy(result + prefix_length, source, source_length);
+  memcpy(result + prefix_length + source_length, suffix, suffix_length);
+
+  result[total_length] = '\0';
+
+  return result;
+}
+
+bool image_tag_supports_block(void) {
+  return false;
+}
+
+const tag_helper_handler_T image_tag_handler = { .name = "image_tag",
+                                                 .source =
+                                                   HB_STRING_LITERAL("ActionView::Helpers::AssetTagHelper#image_tag"),
+                                                 .detect = detect_image_tag,
+                                                 .extract_tag_name = extract_image_tag_name,
+                                                 .extract_content = extract_image_tag_content,
+                                                 .supports_block = image_tag_supports_block };

src/analyze/action_view/registry.c

@@ -10,8 +10,9 @@ extern const tag_helper_handler_T link_to_handler;
 extern const tag_helper_handler_T turbo_frame_tag_handler;
 extern const tag_helper_handler_T javascript_tag_handler;
 extern const tag_helper_handler_T javascript_include_tag_handler;
+extern const tag_helper_handler_T image_tag_handler;
 
-static size_t handlers_count = 6;
+static size_t handlers_count = 7;
 
 tag_helper_info_T* tag_helper_info_init(hb_allocator_T* allocator) {
   tag_helper_info_T* info = hb_allocator_alloc(allocator, sizeof(tag_helper_info_T));
@@ -43,7 +44,7 @@ void tag_helper_info_free(tag_helper_info_T** info) {
 }
 
 tag_helper_handler_T* get_tag_helper_handlers(void) {
-  static tag_helper_handler_T static_handlers[6];
+  static tag_helper_handler_T static_handlers[7];
   static bool initialized = false;
 
   if (!initialized) {
@@ -53,6 +54,8 @@ tag_helper_handler_T* get_tag_helper_handlers(void) {
     static_handlers[3] = turbo_frame_tag_handler;
     static_handlers[4] = javascript_tag_handler;
     static_handlers[5] = javascript_include_tag_handler;
+    static_handlers[6] = image_tag_handler;
+
     initialized = true;
   }
 

src/analyze/action_view/tag_helpers.c

@@ -29,6 +29,10 @@ extern bool detect_javascript_include_tag(pm_call_node_t*, pm_parser_t*);
 extern char* extract_javascript_include_tag_src(pm_call_node_t*, pm_parser_t*, hb_allocator_T*);
 extern char* wrap_in_javascript_path(const char*, size_t, hb_allocator_T*);
 extern bool javascript_include_tag_source_is_url(const char*, size_t);
+extern bool detect_image_tag(pm_call_node_t*, pm_parser_t*);
+extern char* extract_image_tag_src(pm_call_node_t*, pm_parser_t*, hb_allocator_T*);
+extern char* wrap_in_image_path(const char*, size_t, hb_allocator_T*);
+extern bool image_tag_source_is_url(const char*, size_t);
 
 typedef struct {
   pm_parser_t parser;
@@ -360,6 +364,50 @@ static AST_NODE_T* transform_tag_helper_with_attributes(
     }
   }
 
+  if (detect_image_tag(parse_context->info->call_node, &parse_context->parser)
+      && parse_context->info->call_node->arguments && parse_context->info->call_node->arguments->arguments.size >= 1) {
+    char* source_value = extract_image_tag_src(parse_context->info->call_node, &parse_context->parser, allocator);
+
+    if (source_value) {
+      if (!attributes) { attributes = hb_array_init(4, allocator); }
+
+      pm_node_t* first_argument = parse_context->info->call_node->arguments->arguments.nodes[0];
+      position_T source_start, source_end;
+      prism_node_location_to_positions(&first_argument->location, parse_context, &source_start, &source_end);
+      bool source_is_string = (first_argument->type == PM_STRING_NODE);
+      bool source_is_path_helper = is_route_helper_node(first_argument, &parse_context->parser);
+
+      size_t source_length = strlen(source_value);
+      bool is_url = image_tag_source_is_url(source_value, source_length);
+
+      char* source_attribute_value = source_value;
+
+      if (source_is_string && !is_url) {
+        size_t quoted_length = source_length + 2;
+        char* quoted_source = hb_allocator_alloc(allocator, quoted_length + 1);
+        quoted_source[0] = '"';
+        memcpy(quoted_source + 1, source_value, source_length);
+        quoted_source[quoted_length - 1] = '"';
+        quoted_source[quoted_length] = '\0';
+
+        source_attribute_value = wrap_in_image_path(quoted_source, quoted_length, allocator);
+        hb_allocator_dealloc(allocator, quoted_source);
+      } else if (!source_is_string && !is_url && !source_is_path_helper) {
+        source_attribute_value = wrap_in_image_path(source_value, source_length, allocator);
+      }
+
+      AST_HTML_ATTRIBUTE_NODE_T* source_attribute =
+        is_url
+          ? create_html_attribute_node("src", source_attribute_value, source_start, source_end, allocator)
+          : create_html_attribute_with_ruby_literal("src", source_attribute_value, source_start, source_end, allocator);
+
+      if (source_attribute) { attributes = prepend_attribute(attributes, (AST_NODE_T*) source_attribute, allocator); }
+      if (source_attribute_value != source_value) { hb_allocator_dealloc(allocator, source_attribute_value); }
+
+      hb_allocator_dealloc(allocator, source_value);
+    }
+  }
+
   token_T* tag_name_token =
     tag_name ? create_synthetic_token(allocator, tag_name, TOKEN_IDENTIFIER, tag_name_start, tag_name_end) : NULL;
 
@@ -378,7 +426,8 @@ static AST_NODE_T* transform_tag_helper_with_attributes(
   );
 
   hb_array_T* body = hb_array_init(1, allocator);
-  bool is_void = tag_name && (strcmp(handler->name, "tag") == 0) && is_void_element(hb_string_from_c_string(tag_name));
+  bool is_void = tag_name && ((strcmp(handler->name, "tag") == 0) || (strcmp(handler->name, "image_tag") == 0))
+              && is_void_element(hb_string_from_c_string(tag_name));
 
   if (helper_content) {
     append_body_content_node(