1 files changed, 134 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/parser/stencil-scope.js b/js/src/jit-test/tests/parser/stencil-scope.js
new file mode 100644
index 0000000000..0dc562147a
--- /dev/null
+++ b/js/src/jit-test/tests/parser/stencil-scope.js
@@ -0,0 +1,134 @@
+const optionsFull = {
+    fileName: "compileToStencil-DATA.js",
+    lineNumber: 1,
+    eagerDelazificationStrategy: "ParseEverythingEagerly",
+};
+
+const optionsLazy = {
+    fileName: "compileToStencil-DATA.js",
+    lineNumber: 1,
+    eagerDelazificationStrategy: "OnDemandOnly",
+};
+
+const optionsLazyCache = {
+    fileName: "compileToStencil-DATA.js",
+    lineNumber: 1,
+    eagerDelazificationStrategy: "ConcurrentDepthFirst",
+};
+
+const optionsLazyCache2 = {
+    fileName: "compileToStencil-DATA.js",
+    lineNumber: 1,
+    eagerDelazificationStrategy: "ConcurrentLargeFirst",
+};
+
+let result = 0;
+
+function testMainThread(script_str) {
+    const stencil = compileToStencil(script_str, optionsFull);
+    result = evalStencil(stencil, optionsFull);
+    assertEq(result, 1);
+}
+
+function testMainThreadDelazifyAll(script_str) {
+    if (isLcovEnabled()) {
+      // Code-coverage implies forceFullParse = true, and as such it cannot be
+      // used while testing to incrementally delazify.
+      return;
+    }
+    const stencil = compileToStencil(script_str, optionsLazy);
+    result = evalStencil(stencil, optionsLazy);
+    assertEq(result, 1);
+}
+
+function testMainThreadCacheAll(script_str) {
+  if (isLcovEnabled() || helperThreadCount() === 0) {
+    // Code-coverage implies forceFullParse = true, and as such it cannot be
+    // used while testing to incrementally delazify.
+    // Similarly, concurrent delazification requires off-threads processing.
+    return;
+  }
+  const stencil = compileToStencil(script_str, optionsLazyCache);
+  result = evalStencil(stencil, optionsLazyCache);
+  assertEq(result, 1);
+}
+
+function testMainThreadCacheAll2(script_str) {
+  if (isLcovEnabled() || helperThreadCount() === 0) {
+    // Code-coverage implies forceFullParse = true, and as such it cannot be
+    // used while testing to incrementally delazify.
+    // Similarly, concurrent delazification requires off-threads processing.
+    return;
+  }
+  const stencil = compileToStencil(script_str, optionsLazyCache2);
+  result = evalStencil(stencil, optionsLazyCache2);
+  assertEq(result, 1);
+}
+
+function testOffThread(script_str) {
+    const job = offThreadCompileToStencil(script_str, optionsFull);
+    const stencil = finishOffThreadStencil(job);
+    result = evalStencil(stencil, optionsFull);
+    assertEq(result, 1);
+}
+
+// These patches are meant to wrap the inner code given as argument into one
+// kind of scope. The freeVars specify one way to retrieve the variable name
+// added in this process if any.
+const scopeCases = [
+    { code: inner => `{ ${inner} }`, freeVars: [] },
+    { code: inner => `{ var v = 1; ${inner} }`, freeVars: ["v"] },
+    { code: inner => `{ let l = 1; ${inner} }`, freeVars: ["l"] },
+    { code: inner => `{ const c = 1; ${inner} }`, freeVars: ["c"] },
+    { code: inner => `with ({ p: 1 }) { ${inner} }`, freeVars: ["p"],
+      inClass: false },
+    { code: inner => `(a => { ${inner} })(1)`, freeVars: ["a"] },
+    { code: inner => `function fun(a) { ${inner} }; fun(1)`, freeVars: ["a"],
+      inClass: false},
+    { code: inner => `try { ${inner} } catch(unused) { }`, freeVars: [] },
+    { code: inner => `try { throw 1; } catch(t) { ${inner} }`, freeVars: ["t"] },
+    { code: inner => `{ class C { #m = 1; constructor() { ${inner} }}; new C() }`,
+      freeVars: ["this.#m"], isClass: true },
+];
+
+// This function is used to generate code which mostly exercise the various kind
+// of scopes to cover ScopeContext class in CompilationStencil.h
+function generateCode(seed) {
+    let start = inner => `
+      ${inner};
+      result
+    `;
+
+    let prog = [start];
+    let freeVars = ["1"];
+    let inClass = false;
+
+    while (seed >= freeVars.length) {
+        let index = seed % scopeCases.length;
+        seed = (seed / scopeCases.length) | 0;
+        let scope = scopeCases[index];
+        if (inClass && !(scope.inClass ?? false)) {
+            // Skip illegal code (non-strict) or code which might not accept
+            // this to work.
+            continue;
+        }
+        inClass ||= scope.isClass ?? false;
+        prog.push(scope.code);
+        freeVars = freeVars.concat(scope.freeVars);
+    }
+
+    let name = freeVars[seed];
+    return prog.reduceRight((inner, f) => f(inner), `result = ${name}`);
+}
+
+for (let s = 0; s < 3000; s++) {
+    let code = generateCode(s);
+    // console.log(s, ":", code);
+    testMainThread(code);
+    testMainThreadDelazifyAll(code);
+    testMainThreadCacheAll(code);
+    testMainThreadCacheAll2(code);
+    if (helperThreadCount() > 0) {
+        testOffThread(code);
+    }
+}