Support dynamic import (take 2) (#395)
* feat: support dynamic import
* Add a couple of tests
* Align with estree/estree#198
* Update escodegen.js
Co-Authored-By: Michael Ficarra <github@michael.ficarra.me>
* Remove outdated "State 3" from comment
* Add test of a SequenceExpression as a dynamic import source
https://github.com/estools/escodegen/pull/395#discussion_r313073705
* Properly parenthesize when used with a higher precedence operator
https://github.com/estools/escodegen/pull/395#discussion_r313074448
diff --git a/escodegen.js b/escodegen.js
index a8d0170..41b3850 100644
--- a/escodegen.js
+++ b/escodegen.js
@@ -2434,7 +2434,15 @@
ModuleSpecifier: function (expr, precedence, flags) {
return this.Literal(expr, precedence, flags);
- }
+ },
+
+ ImportExpression: function(expr, precedence, flag) {
+ return parenthesize([
+ 'import(',
+ this.generateExpression(expr.source, Precedence.Assignment, E_TTT),
+ ')'
+ ], Precedence.Call, precedence);
+ },
};
diff --git a/test/harmony.js b/test/harmony.js
index 2dfeaf9..249bf34 100644
--- a/test/harmony.js
+++ b/test/harmony.js
@@ -6416,8 +6416,111 @@
}
}
}
- }
+ },
+ // https://github.com/tc39/proposal-dynamic-import/#import
+ 'dynamic import': {
+ "import('foo').then(quux);": {
+ generateFrom: {
+ "type": "ExpressionStatement",
+ "expression": {
+ "type": "CallExpression",
+ "callee": {
+ "type": "MemberExpression",
+ "object": {
+ "type": "ImportExpression",
+ "source": {
+ "type": "Literal",
+ "value": "foo"
+ }
+ },
+ "property": {
+ "type": "Identifier",
+ "name": "then"
+ },
+ "computed": false
+ },
+ "arguments": [
+ {
+ "type": "Identifier",
+ "name": "quux"
+ }
+ ]
+ }
+ }
+ },
+
+ "import(('a', 'b'))": {
+ generateFrom: {
+ "type": "ImportExpression",
+ "source": {
+ "type": "SequenceExpression",
+ "expressions": [
+ {
+ "type": "Literal",
+ "value": "a"
+ },
+ {
+ "type": "Literal",
+ "value": "b"
+ }
+ ]
+ }
+ }
+ },
+
+ "new (import('foo'))()": {
+ generateFrom: {
+ "type": "NewExpression",
+ "callee": {
+ "type": "ImportExpression",
+ "source": {
+ "type": "Literal",
+ "value": "foo"
+ }
+ },
+ "arguments": []
+ }
+ },
+
+ "import('foo' + bar).then(quux);": {
+ generateFrom: {
+ "type": "ExpressionStatement",
+ "expression": {
+ "type": "CallExpression",
+ "callee": {
+ "type": "MemberExpression",
+ "object": {
+ "type": "ImportExpression",
+ "source": {
+ "type": "BinaryExpression",
+ "left": {
+ "type": "Literal",
+ "value": "foo"
+ },
+ "operator": "+",
+ "right": {
+ "type": "Identifier",
+ "name": "bar"
+ }
+ }
+ },
+ "property": {
+ "type": "Identifier",
+ "name": "then"
+ },
+ "computed": false
+ },
+ "arguments": [
+ {
+ "type": "Identifier",
+ "name": "quux"
+ }
+ ]
+ }
+ }
+ }
+ }
};
function updateDeeply(target, override) {
