feat: add assign tag

fixtures/let-assign-with-each-scope/compiled.js

@@ -0,0 +1,24 @@
+let out = "";
+let $lineNumber = 1;
+let $filename = "{{__dirname}}index.edge";
+try {
+template.loop(state.users, function (user) {
+out += "\n";
+$lineNumber = 2;
+let index = 0;
+$lineNumber = 3;
+index = index + 1;
+out += "  ";
+$lineNumber = 4;
+out += `${template.escape(index)}`;
+});
+$lineNumber = 6;
+state.index = (state.index || 0) + 1;
+out += "";
+out += "\n";
+$lineNumber = 8;
+out += `${template.escape(state.index)}`;
+} catch (error) {
+template.reThrow(error, $filename, $lineNumber);
+}
+return out;

fixtures/let-assign-with-each-scope/index.edge

@@ -0,0 +1,8 @@
+@each(user in users)
+  @let(index = 0)
+  @assign(index = index + 1)
+  {{ index }}
+@end
+@assign(index = (index || 0) + 1)
+
+{{ index }}

fixtures/let-assign-with-each-scope/index.json

@@ -0,0 +1,3 @@
+{
+  "users": ["virk"]
+}

fixtures/let-assign-with-each-scope/index.txt

@@ -0,0 +1,2 @@
+1
+1

src/tags/assign.ts

@@ -0,0 +1,48 @@
+/*
+ * edge.js
+ *
+ * (c) EdgeJS
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import { expressions } from 'edge-parser'
+import lodash from '@poppinss/utils/lodash'
+
+import { TagContract } from '../types.js'
+import { isSubsetOf, parseJsArg, unallowedExpression } from '../utils.js'
+
+/**
+ * The assign tag is used to re-assign value to an existing variable
+ */
+export const assignTag: TagContract = {
+  block: false,
+  seekable: true,
+  tagName: 'assign',
+  noNewLine: true,
+
+  /**
+   * Compiles else block node to Javascript else statement
+   */
+  compile(parser, buffer, token) {
+    const parsed = parseJsArg(parser, token)
+
+    isSubsetOf(parsed, [expressions.AssignmentExpression], () => {
+      throw unallowedExpression(
+        `Invalid expression for the @assign tag`,
+        token.filename,
+        parser.utils.getExpressionLoc(parsed)
+      )
+    })
+
+    buffer.writeExpression(parser.utils.stringify(parsed), token.filename, token.loc.start.line)
+  },
+
+  /**
+   * Add methods to the template for running the loop
+   */
+  boot(template) {
+    template.macro('setValue', lodash.set)
+  },
+}

src/tags/let.ts

@@ -7,12 +7,11 @@
  * file that was distributed with this source code.
  */
 
-import { EdgeError } from 'edge-error'
 import { expressions } from 'edge-parser'
 import lodash from '@poppinss/utils/lodash'
 
 import { TagContract } from '../types.js'
-import { isSubsetOf, unallowedExpression, parseJsArg } from '../utils.js'
+import { isSubsetOf, unallowedExpression } from '../utils.js'
 
 /**
  * The let tag is used to set runtime values within the template. The value
@@ -74,7 +73,6 @@ export const letTag: TagContract = {
     )}`
 
     buffer.writeExpression(expression, token.filename, token.loc.start.line)
-    parser.stack.defineVariable(key.value)
   },
 
   /**

src/tags/main.ts

@@ -13,6 +13,7 @@ export { eachTag as each } from './each.js'
 export { slotTag as slot } from './slot.js'
 export { elseTag as else } from './else.js'
 export { evalTag as eval } from './eval.js'
+export { assignTag as assign } from './assign.js'
 export { injectTag as inject } from './inject.js'
 export { unlessTag as unless } from './unless.js'
 export { elseIfTag as elseif } from './else_if.js'