docs: add line highlight validation (#14380)

* docs: add line highlight validation

* add to all projects

* fixes

* fixes

* fix

* fixes

www/packages/docs-utils/src/estree-to-js.ts

@@ -9,24 +9,39 @@ import {
   JSXTextExpression,
   LiteralExpression,
   ObjectExpression,
+  TemplateLiteralExpression,
+  VariableDeclaration,
 } from "types"
 
+const ALLOWED_BODY_TYPES = ["ExpressionStatement", "ExportNamedDeclaration"]
+
 export function estreeToJs(estree: Estree) {
   // TODO improve on this utility. Currently it's implemented to work
   // for specific use cases as we don't have a lot of info on other
   // use cases.
   if (
     !estree.body?.length ||
-    estree.body[0].type !== "ExpressionStatement" ||
-    !estree.body[0].expression
+    !estree.body[0].type ||
+    !ALLOWED_BODY_TYPES.includes(estree.body[0].type)
   ) {
     return
   }
 
-  return expressionToJs(estree.body[0].expression)
+  switch (estree.body[0].type) {
+    case "ExpressionStatement":
+      if (!estree.body[0].expression) {
+        return
+      }
+      return expressionToJs(estree.body[0].expression)
+    case "ExportNamedDeclaration":
+      if (!estree.body[0].declaration) {
+        return
+      }
+      return declarationToJs(estree.body[0].declaration)
+  }
 }
 
-function expressionToJs(
+export function expressionToJs(
   expression: Expression
 ): ExpressionJsVar | ExpressionJsVar[] | undefined {
   switch (expression.type) {
@@ -84,5 +99,36 @@ function expressionToJs(
         },
         data: text,
       }
+    case "TemplateLiteral":
+      const templateExpression = expression as TemplateLiteralExpression
+      let value = ""
+      let raw = ""
+      templateExpression.quasis.forEach((quasi) => {
+        value += quasi.value.cooked
+        raw += quasi.value.raw
+      })
+      return {
+        original: {
+          type: "Literal",
+          value,
+          raw,
+        },
+        data: value,
+      }
+  }
+}
+
+function declarationToJs(declaration: VariableDeclaration): {
+  name: string
+  value: ExpressionJsVar | ExpressionJsVar[] | undefined
+} {
+  if (!declaration.declarations.length) {
+    throw new Error("No declarations found")
+  }
+  const name = declaration.declarations[0].id.name
+  const value = expressionToJs(declaration.declarations[0].init)
+  return {
+    name,
+    value,
   }
 }