transpiler package to replace eval package

packages/transpiler/transpiler.mjs

@@ -0,0 +1,100 @@
+import escodegen from 'escodegen';
+import { parse } from 'acorn';
+import { walk } from 'estree-walker';
+import { isNote } from '@strudel.cycles/core';
+
+export function transpiler(input, options = {}) {
+  const { wrapAsync = true, addReturn = true } = options;
+
+  let ast = parse(input, {
+    ecmaVersion: 2022,
+    allowAwaitOutsideFunction: true,
+  });
+
+  walk(ast, {
+    enter(node, parent, prop, index) {
+      if (isBackTickString(node, parent)) {
+        const { quasis, start, end } = node;
+        const { raw } = quasis[0].value;
+        this.skip();
+        return this.replace(miniWithLocation(raw, start, end));
+      }
+      if (isStringWithDoubleQuotes(node)) {
+        const { value, start, end } = node;
+        this.skip();
+        return this.replace(miniWithLocation(value, start, end));
+      }
+      if (node.type === 'Identifier' && isNote(node.name)) {
+        this.skip();
+        return this.replace({ type: 'Literal', value: node.name });
+      }
+      // TODO:
+    },
+    leave(node, parent, prop, index) {},
+  });
+
+  const { body } = ast;
+  if (!body?.[body.length - 1]?.expression) {
+    throw new Error('unexpected ast format without body expression');
+  }
+
+  // add return to last statement
+  if (addReturn) {
+    const { expression } = body[body.length - 1];
+    body[body.length - 1] = {
+      type: 'ReturnStatement',
+      argument: expression,
+    };
+  }
+  const output = escodegen.generate(ast);
+  if (wrapAsync) {
+    return `(async ()=>{${output}})()`;
+  }
+  return output;
+}
+
+function isStringWithDoubleQuotes(node, locations, code) {
+  const { raw, type } = node;
+  if (type !== 'Literal') {
+    return false;
+  }
+  return raw[0] === '"';
+}
+
+function isBackTickString(node, parent) {
+  return node.type === 'TemplateLiteral' && parent.type !== 'TaggedTemplateExpression';
+}
+
+function miniWithLocation(value, start, end) {
+  // with location
+  return {
+    type: 'CallExpression',
+    callee: {
+      type: 'MemberExpression',
+      object: {
+        type: 'CallExpression',
+        callee: {
+          type: 'Identifier',
+          name: 'mini',
+        },
+        arguments: [{ type: 'Literal', value }],
+        optional: false,
+      },
+      property: {
+        type: 'Identifier',
+        name: 'withMiniLocation',
+      },
+    },
+    arguments: [
+      {
+        type: 'Literal',
+        value: start,
+      },
+      {
+        type: 'Literal',
+        value: end,
+      },
+    ],
+    optional: false,
+  };
+}