move to src directory

src/rewrite/js.js

@@ -0,0 +1,93 @@
+import { parseScript } from 'meriyah';
+// import { parse } from 'acorn-hammerhead';
+import { generate } from 'esotope-hammerhead';
+import EventEmitter from './events.js';
+
+class JS extends EventEmitter {
+    constructor() {
+        super();
+        /*
+        this.parseOptions = { 
+            allowReturnOutsideFunction: true, 
+            allowImportExportEverywhere: true, 
+            ecmaVersion: 2021, 
+        };
+        */
+        this.parseOptions = {
+            ranges: true,
+            module: true,
+            globalReturn: true,
+        };
+        this.generationOptions = {
+            format: {
+                quotes: 'double',
+                escapeless: true,
+                compact: true,
+            },
+        };
+        this.parse = parseScript /*parse*/;
+        this.generate = generate;
+    };  
+    rewrite(str, data = {}) {
+        return this.recast(str, data, 'rewrite');
+    };
+    source(str, data = {}) {
+        return this.recast(str, data, 'source');
+    };
+    recast(str, data = {}, type = '') {
+        try {
+            const output = [];
+            const ast = this.parse(str, this.parseOptions);
+            const meta = {
+                data,
+                changes: [],
+                input: str,
+                ast,
+                get slice() {
+                    return slice;
+                },
+            };
+            let slice = 0;
+
+            this.iterate(ast, (node, parent = null) => {
+                if (parent && parent.inTransformer) node.isTransformer = true;
+                node.parent = parent;
+
+                this.emit(node.type, node, meta, type);
+            });
+
+            meta.changes.sort((a, b) => (a.start - b.start) || (a.end - b.end));
+
+            for (const change of meta.changes) {
+                if ('start' in change && typeof change.start === 'number') output.push(str.slice(slice, change.start));
+                if (change.node) output.push(typeof change.node === 'string' ? change.node : generate(change.node, this.generationOptions));
+                if ('end' in change && typeof change.end === 'number') slice = change.end;
+            };
+            output.push(str.slice(slice));
+            return output.join('');
+        } catch(e) {
+            return str;
+        };
+    };
+    iterate(ast, handler) {
+        if (typeof ast != 'object' || !handler) return;
+        walk(ast, null, handler);
+        function walk(node, parent, handler) {
+            if (typeof node != 'object' || !handler) return;
+            handler(node, parent, handler);
+            for (const child in node) {
+                if (child === 'parent') continue;
+                if (Array.isArray(node[child])) {
+                    node[child].forEach(entry => { 
+                        if (entry) walk(entry, node, handler)
+                    });
+                } else {
+                    if (node[child]) walk(node[child], node, handler);
+                };
+            };
+            if (typeof node.iterateEnd === 'function') node.iterateEnd();
+        };
+    };
+};
+
+export default JS;