Infer and merge variable types with multiple assignments in conditional statements

compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java

Index: compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
diff --git a/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java b/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
index 954c764c03f1701747edc44fbd56d5e04cad33e3..d2c58b6599818fe4c82352101b01348c9c51faa9 100644
--- a/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
+++ b/compiler/javatests/com/google/dart/compiler/type/TypeAnalyzerCompilerTest.java
@@ -1978,26 +1978,156 @@ public class TypeAnalyzerCompilerTest extends CompilerTestCase {
     }
   }
 
-  public void test_typesPropagation_secondAssign_sameType() throws Exception {
+  public void test_typesPropagation_multiAssign() throws Exception {
     analyzeLibrary(
         "// filler filler filler filler filler filler filler filler filler filler",
         "f() {",
         "  var v = true;",
-        "  v = false;",
+        "  var v1 = v;",
+        "  v = 0;",
+        "  var v2 = v;",
         "}",
         "");
-    assertInferredElementTypeString(testUnit, "v", "bool");
+    assertInferredElementTypeString(testUnit, "v1", "bool");
+    assertInferredElementTypeString(testUnit, "v2", "int");
   }
 
-  public void test_typesPropagation_secondAssign_differentType() throws Exception {
+  public void test_typesPropagation_multiAssign_noInitialValue() throws Exception {
     analyzeLibrary(
         "// filler filler filler filler filler filler filler filler filler filler",
         "f() {",
-        "  var v = true;",
+        "  var v;",
         "  v = 0;",
+        "  var v1 = v;",
+        "}",
+        "");
+    assertInferredElementTypeString(testUnit, "v1", "int");
+  }
+
+  public void test_typesPropagation_multiAssign_IfThen() throws Exception {
+    analyzeLibrary(
+        "// filler filler filler filler filler filler filler filler filler filler",
+        "f() {",
+        "  var v = true;",
+        "  var v1 = v;",
+        "  if (true) {",
+        "    v = 0;",
+        "    var v2 = v;",
+        "  }",
+        "  var v3 = v;",
+        "}",
+        "");
+    assertInferredElementTypeString(testUnit, "v1", "bool");
+    assertInferredElementTypeString(testUnit, "v2", "int");
+    assertInferredElementTypeString(testUnit, "v3", "Object");
+  }
+
+  public void test_typesPropagation_multiAssign_IfThenElse() throws Exception {
+    analyzeLibrary(
+        "// filler filler filler filler filler filler filler filler filler filler",
+        "f() {",
+        "  var a = true;",
+        "  var b = true;",
+        "  var c = true;",
+        "  var d = true;",
+        "  if (true) {",
+        "    a = 0;",
+        "    b = 0;",
+        "  } else {",
+        "    a = 0;",
+        "    c = 0;",
+        "  }",
+        "  var a1 = a;",
+        "  var b1 = b;",
+        "  var c1 = c;",
+        "  var d1 = d;",
+        "}",
+        "");
+    assertInferredElementTypeString(testUnit, "a1", "int");
+    assertInferredElementTypeString(testUnit, "b1", "Object");
+    assertInferredElementTypeString(testUnit, "c1", "Object");
+    assertInferredElementTypeString(testUnit, "d1", "bool");
+  }
+
+  public void test_typesPropagation_multiAssign_While() throws Exception {
+    analyzeLibrary(
+        "// filler filler filler filler filler filler filler filler filler filler",
+        "f() {",
+        "  var v = true;",
+        "  var v1 = v;",
+        "  while (true) {",
+        "    var v2 = v;",
+        "    v = 0;",
+        "    var v3 = v;",
+        "  }",
+        "  var v4 = v;",
+        "}",
+        "");
+    assertInferredElementTypeString(testUnit, "v1", "bool");
+    assertInferredElementTypeString(testUnit, "v2", "bool");
+    assertInferredElementTypeString(testUnit, "v3", "int");
+    assertInferredElementTypeString(testUnit, "v4", "Object");
+  }
+  
+  public void test_typesPropagation_multiAssign_DoWhile() throws Exception {
+    analyzeLibrary(
+        "// filler filler filler filler filler filler filler filler filler filler",
+        "f() {",
+        "  var v = true;",
+        "  var v1 = v;",
+        "  do {",
+        "    var v2 = v;",
+        "    v = 0;",
+        "    var v3 = v;",
+        "  } while (true);",
+        "  var v4 = v;",
+        "}",
+        "");
+    assertInferredElementTypeString(testUnit, "v1", "bool");
+    assertInferredElementTypeString(testUnit, "v2", "bool");
+    assertInferredElementTypeString(testUnit, "v3", "int");
+    assertInferredElementTypeString(testUnit, "v4", "int");
+  }
+
+  public void test_typesPropagation_multiAssign_For() throws Exception {
+    analyzeLibrary(
+        "// filler filler filler filler filler filler filler filler filler filler",
+        "f() {",
+        "  var v = true;",
+        "  var v1 = v;",
+        "  for (int i = 0; i < 10; i++) {",
+        "    var v2 = v;",
+        "    v = 0;",
+        "    var v3 = v;",
+        "  }",
+        "  var v4 = v;",
         "}",
         "");
-    assertInferredElementTypeString(testUnit, "v", "<dynamic>");
+    assertInferredElementTypeString(testUnit, "v1", "bool");
+    assertInferredElementTypeString(testUnit, "v2", "bool");
+    assertInferredElementTypeString(testUnit, "v3", "int");
+    assertInferredElementTypeString(testUnit, "v4", "Object");
+  }
+
+  public void test_typesPropagation_multiAssign_ForIn() throws Exception {
+    analyzeLibrary(
+        "// filler filler filler filler filler filler filler filler filler filler",
+        "f() {",
+        "  var v = true;",
+        "  var v1 = v;",
+        "  List<String> names = [];",
+        "  for (var name in names) {",
+        "    var v2 = v;",
+        "    v = 0;",
+        "    var v3 = v;",
+        "  }",
+        "  var v4 = v;",
+        "}",
+        "");
+    assertInferredElementTypeString(testUnit, "v1", "bool");
+    assertInferredElementTypeString(testUnit, "v2", "bool");
+    assertInferredElementTypeString(testUnit, "v3", "int");
+    assertInferredElementTypeString(testUnit, "v4", "Object");
   }
 
   /**
@@ -2382,6 +2512,36 @@ public class TypeAnalyzerCompilerTest extends CompilerTestCase {
     // we exited "if" Block, so "assert" may be was not executed, so we don't know type
     assertInferredElementTypeString(testUnit, "v5", "<dynamic>");
   }
+  
+  /**
+   * <p>
+   * http://code.google.com/p/dart/issues/detail?id=4410
+   */
+  public void test_typesPropagation_assertIsType_twoVariables() throws Exception {
+    analyzeLibrary(
+        "f(a, b) {",
+        "  while (true) {",
+        "    var a1 = a;",
+        "    var b1 = b;",
+        "    assert(a is String);",
+        "    assert(b is String);",
+        "    var a2 = a;",
+        "    var b2 = b;",
+        "  }",
+        "  var a3 = a;",
+        "  var b3 = b;",
+        "}",
+        "");
+    // we don't know type initially
+    assertInferredElementTypeString(testUnit, "a1", "<dynamic>");
+    assertInferredElementTypeString(testUnit, "b1", "<dynamic>");
+    // after "assert" all next statements know type
+    assertInferredElementTypeString(testUnit, "a2", "String");
+    assertInferredElementTypeString(testUnit, "b2", "String");
+    // we exited "if" Block, so "assert" may be was not executed, so we don't know type
+    assertInferredElementTypeString(testUnit, "a3", "<dynamic>");
+    assertInferredElementTypeString(testUnit, "b3", "<dynamic>");
+  }
 
   public void test_typesPropagation_field_inClass_final() throws Exception {
     analyzeLibrary(