test: Start validate parser with random generated AST expressions

cspell.json

@@ -130,7 +130,8 @@
     "Ints",
     "workchain",
     "xffff",
-    "привет"
+    "привет",
+    "letrec"
   ],
   "ignoreRegExpList": [
     "\\b[xB]\\{[a-fA-F0-9]*_?\\}", // binary literals in Fift-asm

package.json

@@ -80,6 +80,7 @@
     "cross-env": "^7.0.3",
     "cspell": "^8.8.3",
     "eslint": "^8.56.0",
+    "fast-check": "^3.23.2",
     "glob": "^8.1.0",
     "husky": "^9.1.5",
     "jest": "^29.3.1",

src/test/prettyPrint/expressions.spec.ts

@@ -0,0 +1,119 @@
+import fc from "fast-check";
+import {
+    AstConditional,
+    AstExpression,
+    AstNumber,
+    AstOpBinary,
+    AstOpUnary,
+    eqExpressions,
+    getAstFactory,
+} from "../../grammar/ast";
+import { prettyPrint } from "../../prettyPrinter";
+import { dummySrcInfo, getParser } from "../../grammar";
+
+describe("Pretty Print Expressions", () => {
+    // Max depth of the expression tree
+    const maxShrinks = 15;
+
+    const generateAstNumber = () =>
+        fc.record({
+            kind: fc.constant("number"),
+            base: fc.constantFrom(2, 8, 10, 16),
+            value: fc.bigInt().filter((n) => n > 0),
+            id: fc.constant(0),
+            loc: fc.constant(dummySrcInfo),
+        }) as fc.Arbitrary<AstNumber>;
+
+    const generateAstOpUnary = (expression: fc.Arbitrary<AstExpression>) =>
+        fc.record({
+            kind: fc.constant("op_unary"),
+            op: fc.constantFrom("+", "-", "!", "!!", "~"),
+            operand: expression,
+            id: fc.constant(0),
+            loc: fc.constant(dummySrcInfo),
+        }) as fc.Arbitrary<AstOpUnary>;
+
+    const generateAstOpBinary = (expression: fc.Arbitrary<AstExpression>) =>
+        fc.record({
+            kind: fc.constant("op_binary"),
+            op: fc.constantFrom(
+                "+",
+                "-",
+                "*",
+                "/",
+                "!=",
+                ">",
+                "<",
+                ">=",
+                "<=",
+                "==",
+                "&&",
+                "||",
+                "%",
+                "<<",
+                ">>",
+                "&",
+                "|",
+                "^",
+            ),
+            left: expression,
+            right: expression,
+            id: fc.constant(0),
+            loc: fc.constant(dummySrcInfo),
+        }) as fc.Arbitrary<AstOpBinary>;
+
+    const generateAstConditional = (expression: fc.Arbitrary<AstExpression>) =>
+        fc.record({
+            kind: fc.constant("conditional"),
+            condition: expression,
+            thenBranch: expression,
+            elseBranch: expression,
+            id: fc.constant(0),
+            loc: fc.constant(dummySrcInfo),
+        }) as fc.Arbitrary<AstConditional>;
+
+    const generateAstExpression: fc.Arbitrary<AstExpression> = fc.letrec(
+        (tie) => ({
+            AstExpression: fc.oneof(
+                generateAstNumber(),
+                tie("AstOpUnary") as fc.Arbitrary<AstOpUnary>,
+                tie("AstOpBinary") as fc.Arbitrary<AstOpBinary>,
+                tie("AstConditional") as fc.Arbitrary<AstConditional>,
+            ),
+            AstOpUnary: fc.limitShrink(
+                generateAstOpUnary(
+                    tie("AstExpression") as fc.Arbitrary<AstExpression>,
+                ),
+                maxShrinks,
+            ),
+            AstOpBinary: fc.limitShrink(
+                generateAstOpBinary(
+                    tie("AstExpression") as fc.Arbitrary<AstExpression>,
+                ),
+                maxShrinks,
+            ),
+            AstConditional: fc.limitShrink(
+                generateAstConditional(
+                    tie("AstExpression") as fc.Arbitrary<AstExpression>,
+                ),
+                maxShrinks,
+            ),
+        }),
+    ).AstExpression;
+    it.each([
+        ["AstConditional", generateAstConditional(generateAstExpression)],
+        ["AstOpBinary", generateAstOpBinary(generateAstExpression)],
+        ["AstOpUnary", generateAstOpUnary(generateAstExpression)],
+    ])("should parse random %s expression", (_, astGenerator) => {
+        fc.assert(
+            fc.property(astGenerator, (astBefore) => {
+                const prettyBefore = prettyPrint(astBefore);
+                const astFactory = getAstFactory();
+                const parser = getParser(astFactory);
+                const astAfter = parser.parseExpression(prettyBefore);
+                expect(eqExpressions(astBefore, astAfter)).toBe(true);
+            }),
+            { seed: 1 },
+        );
+    });
+});

yarn.lock

@@ -2756,6 +2756,13 @@ external-editor@^3.1.0:
     iconv-lite "^0.4.24"
     tmp "^0.0.33"
 
+fast-check@^3.23.2:
+  version "3.23.2"
+  resolved "https://registry.npmjs.org/fast-check/-/fast-check-3.23.2.tgz#0129f1eb7e4f500f58e8290edc83c670e4a574a2"
+  integrity sha512-h5+1OzzfCC3Ef7VbtKdcv7zsstUQwUDlYpUTvjeUsJAssPgLn7QzbboPtL5ro04Mq0rPOsMzl7q5hIbRs2wD1A==
+  dependencies:
+    pure-rand "^6.1.0"
+
 fast-deep-equal@^2.0.1:
   version "2.0.1"
   resolved "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-2.0.1.tgz"
@@ -4795,7 +4802,7 @@ pupa@^3.1.0:
   dependencies:
     escape-goat "^4.0.0"
 
-pure-rand@^6.0.0:
+pure-rand@^6.0.0, pure-rand@^6.1.0:
   version "6.1.0"
   resolved "https://registry.npmjs.org/pure-rand/-/pure-rand-6.1.0.tgz"
   integrity sha512-bVWawvoZoBYpp6yIoQtQXHZjmz35RSVHnUOTefl8Vcjr8snTPY1wnpSPMWekcFwbxI6gtmT7rSYPFvz71ldiOA==