Disallow object and array literals, cleanup hasProps

Author: rattrayalex

src/index.js

@@ -684,6 +684,8 @@ export default function (babel) {
       const fnAST = babel.template(fn.toString())({
         [helperName]: uid,
       });
+      fnAST._compact = true;
+      fnAST._generated = true;
       helpers.push(fnAST);
     }
     insertAfterImports(path, helpers);
@@ -850,6 +852,11 @@ export default function (babel) {
     } else if (path.isLiteral() || isUndefined(path) || isSignedNumber(path)) {
       const isEq = t.binaryExpression("===", argRef, path.node);
       path.replaceWith(isEq);
+    } else if (path.isObjectExpression() || path.isArrayExpression()) {
+      throw path.buildCodeFrameError(
+        "LightScript does not yet support matching on object or array literals. " +
+        "To destructure, use `with` (eg; `| with { foo, bar }: foo + bar`)."
+      );
     }
   }
 
@@ -896,7 +903,7 @@ export default function (babel) {
         }
       }
 
-      const isObjCall = t.callExpression(isObjUid, [argRef, t.arrayExpression(propsToCheck)]);
+      const isObjCall = t.callExpression(isObjUid, [argRef, ...propsToCheck]);
       test = buildAnd(test, isObjCall);
 
       for (const [ propName, childPatternPath, defaultObj = null ] of childPatterns) {

src/stdlib.js

@@ -12,12 +12,14 @@ export const lightscriptImports = {
 };
 
 export const runtimeHelpers = {
-  hasProps: function hasProps(obj, props) {
-    return (
-      obj != null &&
-      (typeof obj === "object" || typeof obj === "function") &&
-      props.filter(prop => prop in obj).length === props.length
-    );
+  hasProps: function hasProps(obj) {
+    if (obj == null) return false;
+    if (typeof obj !== "object" && typeof obj !== "function") return false;
+    let i = arguments.length;
+    while (--i > 0) {
+      if (!(arguments[i] in obj)) return false;
+    }
+    return true;
   },
   hasLength: function hasLength(arr, minLength, maxLength) {
     minLength = minLength || 0;

test/fixtures/match/arr-pattern/expected.js

@@ -1,8 +1,4 @@
-function _hasLength(arr, minLength, maxLength) {
-  minLength = minLength || 0;
-  maxLength = maxLength != null ? maxLength : Number.MAX_SAFE_INTEGER;
-  return arr != null && typeof arr !== "function" && arr.length === arr.length | 0 && arr.length >= minLength && arr.length <= maxLength;
-}
+function _hasLength(arr, minLength, maxLength) { minLength = minLength || 0; maxLength = maxLength != null ? maxLength : Number.MAX_SAFE_INTEGER; return arr != null && typeof arr !== "function" && arr.length === arr.length | 0 && arr.length >= minLength && arr.length <= maxLength; }
 
 if (_hasLength(x, 0, 0)) {
   const [] = x;
@@ -24,4 +20,4 @@ if (_hasLength(x, 0, 0)) {
   const [[b, d = 'e'], [g,, h], ...j] = x;
 
   [b, d, g, ...j].join('');
-}
+}

test/fixtures/match/illegal-arr-expr/actual.js

@@ -0,0 +1,2 @@
+match x:
+  | 1 or [a, b]: "not allowed"

test/fixtures/match/illegal-arr-expr/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "LightScript does not yet support matching on object or array literals. To destructure, use `with` (eg; `| with { foo, bar }: foo + bar`)."
+}

test/fixtures/match/illegal-obj-expr/actual.js

@@ -0,0 +1,2 @@
+match x:
+  | 1 or { a, b: 1 }: "not allowed"

test/fixtures/match/illegal-obj-expr/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "LightScript does not yet support matching on object or array literals. To destructure, use `with` (eg; `| with { foo, bar }: foo + bar`)."
+}

test/fixtures/match/obj-arr-pattern-mixed/actual.js

@@ -0,0 +1,3 @@
+match x:
+  | with { a, aa: [b, { c = 1 }, ...d] }:
+    d.concat(a + b + c)

test/fixtures/match/obj-arr-pattern-mixed/exec.js

@@ -0,0 +1,28 @@
+m(x) -> match x:
+  | with { a, aa: [b, { c = 1 }, ...d] }:
+    d.concat(a + b + c)
+
+assert.equal(
+  undefined,
+  m()
+)
+assert.equal(
+  undefined,
+  m({ a: 1 })
+)
+assert.equal(
+  undefined,
+  m({ a: 1, aa: [ 2 ] })
+)
+assert.deepEqual(
+  [4],
+  m({ a: 1, aa: [ 2, [ 3 ] ] })  // womp, arrays are objects
+)
+assert.deepEqual(
+  [5],
+  m({ a: 1, aa: [ 2, { c: 2 } ] })
+)
+assert.deepEqual(
+  [7, 5],
+  m({ a: 1, aa: [ 2, { c: 2 }, 7 ] })
+)

test/fixtures/match/obj-arr-pattern-mixed/expected.js

@@ -0,0 +1,9 @@
+function _hasProps(obj) { if (obj == null) return false; if (typeof obj !== "object" && typeof obj !== "function") return false; var i = arguments.length; while (--i > 0) { if (!(arguments[i] in obj)) return false; } return true; }
+
+function _hasLength(arr, minLength, maxLength) { minLength = minLength || 0; maxLength = maxLength != null ? maxLength : Number.MAX_SAFE_INTEGER; return arr != null && typeof arr !== "function" && arr.length === arr.length | 0 && arr.length >= minLength && arr.length <= maxLength; }
+
+if (_hasProps(x, "a", "aa") && _hasLength(x.aa, 2) && _hasProps(x.aa[1])) {
+  const { a, aa: [b, { c = 1 }, ...d] } = x;
+
+  d.concat(a + b + c);
+}

test/fixtures/match/obj-pattern/expected.js

@@ -1,31 +1,27 @@
-function _hasProps(obj, props) {
-  return obj != null && (typeof obj === "object" || typeof obj === "function") && props.filter(function (prop) {
-    return prop in obj;
-  }).length === props.length;
-}
+function _hasProps(obj) { if (obj == null) return false; if (typeof obj !== "object" && typeof obj !== "function") return false; var i = arguments.length; while (--i > 0) { if (!(arguments[i] in obj)) return false; } return true; }
 
-if (_hasProps(x, ["a"])) {
+if (_hasProps(x, "a")) {
   const { a } = x;
 
   a;
-} else if (_hasProps(x, ["a", "b"])) {
+} else if (_hasProps(x, "a", "b")) {
   const { a, b } = x;
 
   a + b;
-} else if (_hasProps(x, ["a"])) {
+} else if (_hasProps(x, "a")) {
   const { a, b = 1 } = x;
 
   a + b;
-} else if (_hasProps(x, ["a", "b", "c"]) && _hasProps(x.b, ["ba"]) && _hasProps(x.c, ["ca", "cb"]) && _hasProps(x.c.cb, ["cba"])) {
+} else if (_hasProps(x, "a", "b", "c") && _hasProps(x.b, "ba") && _hasProps(x.c, "ca", "cb") && _hasProps(x.c.cb, "cba")) {
   const { a, b: { ba, bb = 1 }, c: { ca, cb: { cba } } } = x;
 
   a + ba + bb + ca + cba;
-} else if ((x === 1 || x === 2) && _hasProps(x, ["a", "b"]) && _hasProps(x.b, ["c"])) {
+} else if ((x === 1 || x === 2) && _hasProps(x, "a", "b") && _hasProps(x.b, "c")) {
   const { a, b: { c } } = x;
 
   a + c;
-} else if (_hasProps(x, []) && (_hasProps(x.a, ["b"]) && _hasProps(x.a.b, ["c"]) || _hasProps(otherObj, ["b"]) && _hasProps(otherObj.b, ["c"]))) {
+} else if (_hasProps(x) && (_hasProps(x.a, "b") && _hasProps(x.a.b, "c") || _hasProps(otherObj, "b") && _hasProps(otherObj.b, "c"))) {
   const { a: { b: { c } } = otherObj } = x;
 
   c;
-} //TODO: test `| { a, ...b }: b`
+} //TODO: test `| { a, ...b }: b`