Basic tests for javascript.Printers

We're going to do modifications, so we add some tests.
scala-js · gzm0 · Jan 28, 2024 · Dec 28, 2023 · Dec 25, 2023 · Dec 28, 2023
commit e55b62448b4508a13a2f28e9b0dbc4922931d8d2
diff --git a/linker/shared/src/test/scala/org/scalajs/linker/backend/javascript/PrintersTest.scala b/linker/shared/src/test/scala/org/scalajs/linker/backend/javascript/PrintersTest.scala
@@ -0,0 +1,164 @@
+/*
+ * Scala.js (https://www.scala-js.org/)
+ *
+ * Copyright EPFL.
+ *
+ * Licensed under Apache License 2.0
+ * (https://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package org.scalajs.linker.backend.javascript
+
+import scala.language.implicitConversions
+
+import java.nio.charset.StandardCharsets
+
+import org.junit.Test
+import org.junit.Assert._
+
+import org.scalajs.ir
+
+import Trees._
+
+class PrintersTest {
+
+  private implicit val pos: ir.Position = ir.Position.NoPosition
+
+  private implicit def str2ident(name: String): Ident =
+    Ident(name, ir.OriginalName.NoOriginalName)
+
+  private def assertPrintEquals(expected: String, tree: Tree): Unit = {
+    val out = new ByteArrayWriter
+    val printer = new Printers.JSTreePrinter(out)
+    printer.printTopLevelTree(tree)
+    assertEquals(expected.stripMargin.trim + "\n",
+        new String(out.toByteArray(), StandardCharsets.UTF_8))
+  }
+
+  @Test def printFunctionDef(): Unit = {
+    assertPrintEquals(
+        """
+          |function test() {
+          |  const x = 2;
+          |  return x
+          |}
+        """,
+        FunctionDef("test", Nil, None, Block(
+          Let("x", mutable = false, Some(IntLiteral(2))),
+          Return(VarRef("x"))))
+    )
+
+    assertPrintEquals(
+        """
+          |function test() {
+          |  /*<skip>*/
+          |}
+        """,
+        FunctionDef("test", Nil, None, Skip())
+    )
+  }
+
+  @Test def printClassDef(): Unit = {
+    assertPrintEquals(
+        """
+          |class MyClass extends foo.Other {
+          |}
+        """,
+        ClassDef(Some("MyClass"), Some(DotSelect(VarRef("foo"), "Other")), Nil)
+    )
+
+    assertPrintEquals(
+        """
+          |class MyClass {
+          |  foo() {
+          |    /*<skip>*/
+          |  };
+          |  get a() {
+          |    return 1
+          |  };
+          |  set a(x) {
+          |    /*<skip>*/
+          |  };
+          |}
+        """,
+        ClassDef(Some("MyClass"), None, List(
+          MethodDef(false, "foo", Nil, None, Skip()),
+          GetterDef(false, "a", Return(IntLiteral(1))),
+          SetterDef(false, "a", ParamDef("x"), Skip())
+        ))
+    )
+  }
+
+  @Test def printDocComment(): Unit = {
+    assertPrintEquals(
+      """
+        | /** test */
+      """,
+      DocComment("test")
+    )
+  }
+
+  @Test def printFor(): Unit = {
+    assertPrintEquals(
+      """
+        |for (let x = 1; (x < 15); x = (x + 1)) {
+        |  /*<skip>*/
+        |};
+      """,
+      For(Let("x", true, Some(IntLiteral(1))),
+          BinaryOp(ir.Trees.JSBinaryOp.<, VarRef("x"), IntLiteral(15)),
+          Assign(VarRef("x"), BinaryOp(ir.Trees.JSBinaryOp.+, VarRef("x"), IntLiteral(1))),
+          Skip())
+    )
+  }
+
+  @Test def printForIn(): Unit = {
+    assertPrintEquals(
+      """
+        |for (var x in foo) {
+        |  /*<skip>*/
+        |};
+      """,
+      ForIn(VarDef("x", None), VarRef("foo"), Skip())
+    )
+  }
+
+  @Test def printIf(): Unit = {
+    assertPrintEquals(
+        """
+          |if (false) {
+          |  1
+          |};
+        """,
+        If(BooleanLiteral(false), IntLiteral(1), Skip())
+    )
+
+    assertPrintEquals(
+        """
+          |if (false) {
+          |  1
+          |} else {
+          |  2
+          |};
+        """,
+        If(BooleanLiteral(false), IntLiteral(1), IntLiteral(2))
+    )
+
+    assertPrintEquals(
+        """
+          |if (false) {
+          |  1
+          |} else if (true) {
+          |  2
+          |} else {
+          |  3
+          |};
+        """,
+        If(BooleanLiteral(false), IntLiteral(1),
+            If(BooleanLiteral(true), IntLiteral(2), IntLiteral(3)))
+    )
+  }
+}