1 files changed, 90 insertions, 0 deletions
diff --git a/src/compiler/transform/prism.ts b/src/compiler/transform/prism.ts
new file mode 100644
index 000000000..628dcce7e
--- /dev/null
+++ b/src/compiler/transform/prism.ts
@@ -0,0 +1,90 @@
+import type { Transformer } from '../../@types/transformer';
+import type { Script } from '../../parser/interfaces';
+import { getAttrValue } from '../../ast.js';
+
+const PRISM_IMPORT = `import Prism from 'astro/components/Prism.astro';\n`;
+const prismImportExp = /import Prism from ['"]astro\/components\/Prism.astro['"]/;
+
+function escape(code: string) {
+  return code.replace(/[`$]/g, (match) => {
+    return '\\' + match;
+  });
+}
+
+export default function (module: Script): Transformer {
+  let usesPrism = false;
+
+  return {
+    visitors: {
+      html: {
+        Element: {
+          enter(node) {
+            if (node.name !== 'code') return;
+            const className = getAttrValue(node.attributes, 'class') || '';
+            const classes = className.split(' ');
+
+            let lang;
+            for (let cn of classes) {
+              const matches = /language-(.+)/.exec(cn);
+              if (matches) {
+                lang = matches[1];
+              }
+            }
+
+            if (!lang) return;
+
+            let code;
+            if (node.children?.length) {
+              code = node.children[0].data;
+            }
+
+            const repl = {
+              start: 0,
+              end: 0,
+              type: 'InlineComponent',
+              name: 'Prism',
+              attributes: [
+                {
+                  type: 'Attribute',
+                  name: 'lang',
+                  value: [
+                    {
+                      type: 'Text',
+                      raw: lang,
+                      data: lang,
+                    },
+                  ],
+                },
+                {
+                  type: 'Attribute',
+                  name: 'code',
+                  value: [
+                    {
+                      type: 'MustacheTag',
+                      expression: {
+                        type: 'Expression',
+                        codeStart: '`' + escape(code) + '`',
+                        codeEnd: '',
+                        children: []
+                      }
+                    },
+                  ],
+                },
+              ],
+              children: [],
+            };
+
+            this.replace(repl);
+            usesPrism = true;
+          },
+        },
+      },
+    },
+    async finalize() {
+      // Add the Prism import if needed.
+      if (usesPrism && !prismImportExp.test(module.content)) {
+        module.content = PRISM_IMPORT + module.content;
+      }
+    },
+  };
+}