Refactor js embed print to use test/print pattern (#17963)

src/language-js/embed/css.js

@@ -157,15 +157,10 @@ function isCssProp({ parent, grandparent }) {
   );
 }
 
-function printCss(path /* , options*/) {
-  if (
-    isStyledJsx(path) ||
-    isStyledComponents(path) ||
-    isCssProp(path) ||
-    isAngularComponentStyles(path)
-  ) {
-    return printEmbedCss;
-  }
-}
+const isEmbedCss = (path /* , options*/) =>
+  isStyledJsx(path) ||
+  isStyledComponents(path) ||
+  isCssProp(path) ||
+  isAngularComponentStyles(path);
 
-export default printCss;
+export { isEmbedCss, printEmbedCss };

src/language-js/embed/graphql.js

@@ -105,7 +105,7 @@ function printGraphqlComments(lines) {
  * This intentionally excludes Relay Classic tags, as Prettier does not
  * support Relay Classic formatting.
  */
-function isGraphQL({ node, parent }) {
+function isEmbedGraphQL({ node, parent }) {
   return (
     hasLanguageComment({ node, parent }, "GraphQL") ||
     (parent &&
@@ -121,10 +121,4 @@ function isGraphQL({ node, parent }) {
   );
 }
 
-function printGraphql(path /* , options*/) {
-  if (isGraphQL(path)) {
-    return printEmbedGraphQL;
-  }
-}
-
-export default printGraphql;
+export { isEmbedGraphQL, printEmbedGraphQL };

src/language-js/embed/html.js

@@ -106,7 +106,7 @@ async function printEmbedHtmlLike(parser, textToDoc, print, path, options) {
  *     - html`...`
  *     - HTML comment block
  */
-function isHtml(path) {
+function isEmbedHtml(path) {
   return (
     hasLanguageComment(path, "HTML") ||
     path.match(
@@ -123,14 +123,9 @@ function isHtml(path) {
 const printEmbedHtml = printEmbedHtmlLike.bind(undefined, "html");
 const printEmbedAngular = printEmbedHtmlLike.bind(undefined, "angular");
 
-function printHtml(path /* , options*/) {
-  if (isHtml(path)) {
-    return printEmbedHtml;
-  }
-
-  if (isAngularComponentTemplate(path)) {
-    return printEmbedAngular;
-  }
-}
-
-export default printHtml;
+export {
+  isAngularComponentTemplate,
+  isEmbedHtml,
+  printEmbedAngular,
+  printEmbedHtml,
+};

src/language-js/embed/index.js

@@ -1,8 +1,24 @@
 import { label } from "../../document/builders.js";
-import printCss from "./css.js";
-import printGraphQL from "./graphql.js";
-import printHtml from "./html.js";
-import printMarkdown from "./markdown.js";
+import { isEmbedCss, printEmbedCss } from "./css.js";
+import { isEmbedGraphQL, printEmbedGraphQL } from "./graphql.js";
+import {
+  isAngularComponentTemplate,
+  isEmbedHtml,
+  printEmbedAngular,
+  printEmbedHtml,
+} from "./html.js";
+import { isEmbedMarkdown, printEmbedMarkdown } from "./markdown.js";
+
+const printers = [
+  { test: isEmbedCss, print: printEmbedCss },
+  { test: isEmbedGraphQL, print: printEmbedGraphQL },
+  { test: isEmbedHtml, print: printEmbedHtml },
+  { test: isAngularComponentTemplate, print: printEmbedAngular },
+  { test: isEmbedMarkdown, print: printEmbedMarkdown },
+].map(({ test, print }) => ({
+  test,
+  print: createTemplateLiteralPrint(print),
+}));
 
 function embed(path) {
   const { node } = path;
@@ -16,29 +32,28 @@ function embed(path) {
     return;
   }
 
-  let embedder;
-  for (const getEmbedder of [
-    printCss,
-    printGraphQL,
-    printHtml,
-    printMarkdown,
-  ]) {
-    embedder = getEmbedder(path);
+  const printer = printers.find(({ test }) => test(path));
 
-    if (!embedder) {
-      continue;
-    }
-
-    // Special case: whitespace-only template literals
-    if (node.quasis.length === 1 && node.quasis[0].value.raw.trim() === "") {
-      return "``";
-    }
-
-    return async (...args) => {
-      const doc = await embedder(...args);
-      return doc && label({ embed: true, ...doc.label }, doc);
-    };
+  if (!printer) {
+    return;
   }
+
+  if (
+    // Special case: whitespace-only template literals
+    node.quasis.length === 1 &&
+    node.quasis[0].value.raw.trim() === ""
+  ) {
+    return "``";
+  }
+
+  return printer.print;
+}
+
+function createTemplateLiteralPrint(print) {
+  return async (...args) => {
+    const doc = await print(...args);
+    return doc && label({ embed: true, ...doc.label }, doc);
+  };
 }
 
 function hasInvalidCookedValue({ quasis }) {

src/language-js/embed/markdown.js

@@ -34,17 +34,11 @@ function getIndentation(str) {
   return firstMatchedIndent === null ? "" : firstMatchedIndent[1];
 }
 
-function printMarkdown(path /* , options*/) {
-  if (isMarkdown(path)) {
-    return printEmbedMarkdown;
-  }
-}
-
 /**
  * md`...`
  * markdown`...`
  */
-function isMarkdown({ node, parent }) {
+function isEmbedMarkdown({ node, parent }) {
   return (
     parent?.type === "TaggedTemplateExpression" &&
     node.quasis.length === 1 &&
@@ -53,4 +47,4 @@ function isMarkdown({ node, parent }) {
   );
 }
 
-export default printMarkdown;
+export { isEmbedMarkdown, printEmbedMarkdown };