Convert IfThenToElvisIntention to inspection & decrease severity to INFO

#KT-16067 Fixed
2019-06-03 20:27:35 +07:00
parent d8f32b1a0c
commit f2accb7b9e
101 changed files with 498 additions and 487 deletions
@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.branchedTransformations.IfThenToElvisInspection
@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun test(): String? {
+    var foo = maybeFoo()
+    val bar = if (foo == null<caret>)
+        "hello"
+    else
+        foo
+    return foo
+}
@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun test(): String? {
+    var foo = maybeFoo()
+    val bar = foo ?: "hello"
+    return foo
+}
@@ -0,0 +1,15 @@
+// PROBLEM: none
+fun <T> doSomething(a: T) {}
+
+fun main(args: Array<String>) {
+    val foo: String? = null
+    val bar = "bar"
+
+    if (foo != null<caret>) {
+        doSomething ("Hello")
+        foo
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,14 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo = null
+    val a = "a"
+    val b = "b"
+
+    if (foo != null<caret>) {
+        a
+    }
+    else {
+        b
+    }
+
+}
@@ -0,0 +1,9 @@
+// See KT-15227
+class My(val local: Boolean)
+
+class Your(val my: My?, val parent: Any?)
+
+fun foo(your: Your): Boolean {
+    val my = your.my
+    return <caret>if (my != null) my.local else your.parent != null
+}
@@ -0,0 +1,9 @@
+// See KT-15227
+class My(val local: Boolean)
+
+class Your(val my: My?, val parent: Any?)
+
+fun foo(your: Your): Boolean {
+    val my = your.my
+    return my?.local ?: (your.parent != null)
+}
@@ -0,0 +1,10 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = "foo"
+    if (null == <caret>null) {
+        foo
+    }
+    else {
+        null
+    }
+}
@@ -0,0 +1,13 @@
+// PROBLEM: none
+operator fun <T> T.compareTo(a: T): Int = 0
+
+fun main(args: Array<String>) {
+    val foo = null
+    val bar = "bar"
+    if (foo > null<caret>) {
+        foo
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,15 @@
+// PROBLEM: none
+// ERROR: Type mismatch: inferred type is Int but Boolean was expected
+// ERROR: Type mismatch: inferred type is Int but Boolean was expected
+// ERROR: Operator call corresponds to a dot-qualified call 'foo.times(10)' which is not allowed on a nullable receiver 'foo'.
+
+fun main(args: Array<String>) {
+    val foo: Int? = 4
+    val bar = 3
+    if (foo * 10<caret>) {
+        foo
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,8 @@
+// "Replace 'if' expression with elvis expression" "true"
+
+data class IntPair(val first: Int?, val second: Int?)
+
+fun f(pair: IntPair): Int {
+    val (x, y) = pair
+    return if (x != <caret>null) x else 5
+}
@@ -0,0 +1,8 @@
+// "Replace 'if' expression with elvis expression" "true"
+
+data class IntPair(val first: Int?, val second: Int?)
+
+fun f(pair: IntPair): Int {
+    val (x, y) = pair
+    return x ?: 5
+}
@@ -0,0 +1,17 @@
+fun <T> doSomething(a: T) {}
+
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    doSomething(foo)
+    val bar = "bar"
+    if (foo != null<caret>) {
+        foo
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,12 @@
+fun <T> doSomething(a: T) {}
+
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    doSomething(foo)
+    val bar = "bar"
+    foo ?: bar
+}
@@ -0,0 +1,13 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+val x = maybeFoo()
+
+fun main(args: Array<String>) {
+    if (x !=<caret> null) {
+        x
+    } else {
+        "abc"
+    }
+}
@@ -0,0 +1,9 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+val x = maybeFoo()
+
+fun main(args: Array<String>) {
+    x ?: "abc"
+}
@@ -0,0 +1,12 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo = "foo"
+    val bar = "foo"
+    if (<caret>) {
+        foo
+    }
+    else {
+        bar
+    }
+
+}
@@ -0,0 +1,10 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = null
+    if (foo != null<caret>) {
+        foo
+    }
+    else {
+
+    }
+}
@@ -0,0 +1,10 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = "foo"
+    val bar = "bar"
+    if (foo == null<caret>) {
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,5 @@
+class Foo {
+    fun Foo.bar(): Int = 1
+}
+
+fun Foo.test(foo: Foo?): Int = <caret>if (foo == null) { 0 } else { foo.bar() }
@@ -0,0 +1,5 @@
+class Foo {
+    fun Foo.bar(): Int = 1
+}
+
+fun Foo.test(foo: Foo?): Int = foo?.bar() ?: 0
@@ -0,0 +1,14 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    if (foo != null<caret>) {
+        foo
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    maybeFoo() ?: bar
+}
@@ -0,0 +1,12 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    if (foo != null<caret>)
+        foo
+    else
+        bar
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    maybeFoo() ?: bar
+}
@@ -0,0 +1,14 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    val x = if (foo == null<caret>) {
+        bar
+    }
+    else {
+        foo
+    }
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    val x = maybeFoo() ?: bar
+}
@@ -0,0 +1,9 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    val x = "baz" + if (foo == null<caret>) bar else foo
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    val x = "baz" + (maybeFoo() ?: bar)
+}
@@ -0,0 +1,6 @@
+fun foo(arg: Any): Int {
+    // 1
+    return <caret>if (arg is Int) arg
+    // 2
+    else 10
+}
@@ -0,0 +1,6 @@
+fun foo(arg: Any): Int {
+    // 1
+    return arg as? Int
+// 2
+            ?: 10
+}
@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = <caret>if (this == null) true else isEmpty()
@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+fun String?.foo() = this?.isEmpty() ?: true
@@ -0,0 +1,101 @@
+<problems>
+  <problem>
+    <file>ifAsPartOfExpression.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <package>ifAsPartOfExpression</package>
+    <entry_point TYPE="method" FQNAME="ifAsPartOfExpression.IfAsPartOfExpressionKt void main(java.lang.String[] args)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>comparisonInElse.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <package>comparisonInElse</package>
+    <entry_point TYPE="method" FQNAME="comparisonInElse.ComparisonInElseKt boolean foo(comparisonInElse.Your your)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>willNotInlineClassProperty.kt</file>
+    <line>3</line>
+    <module>light_idea_test_case</module>
+    <package>willNotInlineClassProperty</package>
+    <entry_point TYPE="field" FQNAME="willNotInlineClassProperty.F c" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>applicableForLocalStableVar.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <package>applicableForLocalStableVar</package>
+    <entry_point TYPE="method" FQNAME="applicableForLocalStableVar.ApplicableForLocalStableVarKt java.lang.String test()" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>nullCheckWithSelector.kt</file>
+    <line>4</line>
+    <module>light_idea_test_case</module>
+    <package>nullCheckWithSelector</package>
+    <entry_point TYPE="method" FQNAME="nullCheckWithSelector.NullCheckWithSelectorKt int foo(nullCheckWithSelector.My arg)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>nullCheckWithSelectorCall.kt</file>
+    <line>5</line>
+    <module>light_idea_test_case</module>
+    <package>nullCheckWithSelectorCall</package>
+    <entry_point TYPE="field" FQNAME="nullCheckWithSelectorCall.NullCheckWithSelectorCallKt foo" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>implicitReceiver.kt</file>
+    <line>2</line>
+    <module>light_idea_test_case</module>
+    <package>implicitReceiver</package>
+    <entry_point TYPE="method" FQNAME="implicitReceiver.ImplicitReceiverKt boolean foo(java.lang.String $self)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>nullCheckWithSelectorCallChain.kt</file>
+    <line>5</line>
+    <module>light_idea_test_case</module>
+    <package>nullCheckWithSelectorCallChain</package>
+    <entry_point TYPE="field" FQNAME="nullCheckWithSelectorCallChain.NullCheckWithSelectorCallChainKt foo" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>extensionFunctionInClass.kt</file>
+    <line>5</line>
+    <module>light_idea_test_case</module>
+    <package>extensionFunctionInClass</package>
+    <entry_point TYPE="method" FQNAME="extensionFunctionInClass.ExtensionFunctionInClassKt int test(extensionFunctionInClass.Foo $self, extensionFunctionInClass.Foo foo)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>doesNotInlineVariableInMultiDeclaration.kt</file>
+    <line>7</line>
+    <module>light_idea_test_case</module>
+    <package>doesNotInlineVariableInMultiDeclaration</package>
+    <entry_point TYPE="method" FQNAME="doesNotInlineVariableInMultiDeclaration.DoesNotInlineVariableInMultiDeclarationKt int f(doesNotInlineVariableInMultiDeclaration.IntPair pair)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+  <problem>
+    <file>ifAsExpression.kt</file>
+    <line>8</line>
+    <module>light_idea_test_case</module>
+    <package>ifAsExpression</package>
+    <entry_point TYPE="method" FQNAME="ifAsExpression.IfAsExpressionKt void main(java.lang.String[] args)" />
+    <problem_class severity="INFO" attribute_key="INFO_ATTRIBUTES">If-Then foldable to '?:'</problem_class>
+    <description>If-Then foldable to '?:'</description>
+  </problem>
+</problems>
@@ -0,0 +1,2 @@
+// INSPECTION_CLASS: org.jetbrains.kotlin.idea.inspections.branchedTransformations.IfThenToElvisInspection
+// WITH_RUNTIME
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): My {
+    return if (<caret>arg is My) arg else My(42)
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): My {
+    return arg as? My ?: My(42)
+}
@@ -0,0 +1,10 @@
+// PROBLEM: none
+
+fun foo(x: CharSequence?) {
+    val y = if (x is String?) {
+        x
+    }
+    else {
+        (x as CharSequence).toString()
+    }<caret>
+}
@@ -0,0 +1,12 @@
+// PROBLEM: none
+
+interface A
+interface B
+
+fun prepare(x: A) = x
+fun use(x: A) {}
+
+fun test(x: A) {
+    val xx = <caret>if (x is B) x else prepare(x)
+    use(xx)
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): Int {
+    return if (<caret>arg is My) arg.x else 42
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): Int {
+    return (arg as? My)?.x ?: 42
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): Int {
+    return if (<caret>arg is My) arg.x.hashCode() else 42
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): Int {
+    return (arg as? My)?.x?.hashCode() ?: 42
+}
@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+interface Taggable {
+    val tag: String
+}
+
+fun Any.log() {
+    val tag = <caret>if (this is Taggable) {
+        tag
+    }
+    else {
+        this::class.java.simpleName
+    }
+}
@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+interface Taggable {
+    val tag: String
+}
+
+fun Any.log() {
+    val tag = (this as? Taggable)?.tag ?: this::class.java.simpleName
+}
@@ -0,0 +1,12 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    if (foo == null<caret>)
+        bar
+    else
+        foo
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    maybeFoo() ?: bar
+}
@@ -0,0 +1,12 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    val bar = "bar"
+    if (foo != null<caret>)
+        foo
+    else
+        bar
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    maybeFoo() ?: bar
+}
@@ -0,0 +1,7 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = "foo"
+    if (foo == null<caret>) {
+        null
+    }
+}
@@ -0,0 +1,9 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = "foo"
+    val bar = "bar"
+    if (foo != null<caret>)
+    else {
+        bar
+    }
+}
@@ -0,0 +1,8 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = "foo"
+    val bar = "bar"
+    if<caret> {
+        foo
+    } else bar
+}
@@ -0,0 +1,11 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo = "foo"
+    val bar = "bar"
+    if (foo == bar<caret>) {
+        foo
+    }
+    else {
+        bar
+    }
+}
@@ -0,0 +1,11 @@
+// PROBLEM: none
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    if (maybeFoo() == null<caret>)
+        maybeFoo()
+    else
+        "bar"
+}
@@ -0,0 +1,22 @@
+// WITH_RUNTIME
+// PROBLEM: none
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun capture(block: () -> Unit): Unit = Unit
+
+fun test(): String? {
+    var foo = maybeFoo()
+
+    capture {
+        foo = null
+    }
+
+    val bar = if (foo == null<caret>)
+        42
+    else
+        foo
+
+    return foo
+}
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    val t: String? = "abc"
+    if (t != null<caret>) t else throw KotlinNullPointerException()
+}
@@ -0,0 +1,6 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    val t: String? = "abc"
+    if (t == null<caret>) throw NullPointerException() else t
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): My {
+    return if (<caret>arg !is My) My(42) else arg
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: Any?): My {
+    return arg as? My ?: My(42)
+}
@@ -0,0 +1,10 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo: String? = "foo"
+    if (foo == null<caret>) {
+        null
+    }
+    else {
+        foo
+    }
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: My?): Int {
+    return if (<caret>arg != null) arg.x else 42
+}
@@ -0,0 +1,5 @@
+class My(val x: Int)
+
+fun foo(arg: My?): Int {
+    return arg?.x ?: 42
+}
@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+val nullableString: String? = "abc"
+
+val foo = if (<caret>nullableString != null) {
+    nullableString.toUpperCase()
+} else {
+    ""
+}
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+val nullableString: String? = "abc"
+
+val foo = nullableString?.toUpperCase() ?: ""
@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+val nullableString: String? = "abc"
+
+val foo = if (<caret>nullableString != null) {
+    nullableString.toUpperCase().toLowerCase()
+} else {
+    ""
+}
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+
+val nullableString: String? = "abc"
+
+val foo = nullableString?.toUpperCase()?.toLowerCase() ?: ""
@@ -0,0 +1,7 @@
+// PROBLEM: none
+
+class Something {
+    fun nullable(): Int? = null
+}
+fun Something?.nullable(value: Int): Int? =
+    <caret>if (this == null) value else nullable()
@@ -0,0 +1,7 @@
+// PROBLEM: none
+
+fun foo(p: String?): String? {
+    return <caret>if (p != null) p.bar() else "a"
+}
+
+fun String.bar(): String? = null
@@ -0,0 +1,15 @@
+// PROBLEM: none
+fun <T> doSomething(a: T) {}
+
+fun main(args: Array<String>) {
+    val foo: String? = null
+    val bar = "bar"
+
+    if (foo != null<caret>) {
+        foo
+    }
+    else {
+        doSomething("Hello")
+        bar
+    }
+}
@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+fun foo(s: String?) {
+    val x = <caret>if (s != null) {
+        bar(s)
+    }
+    else {
+        13
+    }
+}
+
+fun bar(s: String): Int = 42
@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+fun foo(s: String?) {
+    val x = s?.let { bar(it) } ?: 13
+}
+
+fun bar(s: String): Int = 42
@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+fun foo(it: String?) {
+    val x = <caret>if (it != null) {
+        bar(it)
+    }
+    else {
+        13
+    }
+}
+
+fun bar(s: String): Int = 42
@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+
+fun foo(it: String?) {
+    val x = it?.let { it1 -> bar(it1) } ?: 13
+}
+
+fun bar(s: String): Int = 42
@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+
+class Test {
+    fun doAThing(param1: String): String {
+        return param1
+    }
+
+    fun doAThingIfPresent(param1: String?): String {
+        return <caret>if (param1 != null) {
+            doAThing(param1)
+        } else {
+            ""
+        }
+    }
+}
@@ -0,0 +1,11 @@
+// WITH_RUNTIME
+
+class Test {
+    fun doAThing(param1: String): String {
+        return param1
+    }
+
+    fun doAThingIfPresent(param1: String?): String {
+        return param1?.let { doAThing(it) } ?: ""
+    }
+}
@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+
+class Test {
+    fun doAThing(param1: String): String {
+        return param1
+    }
+
+    fun doAThingIfPresent(param1: Any?): String {
+        return <caret>if (param1 is String) {
+            doAThing(param1)
+        } else {
+            ""
+        }
+    }
+}
@@ -0,0 +1,11 @@
+// WITH_RUNTIME
+
+class Test {
+    fun doAThing(param1: String): String {
+        return param1
+    }
+
+    fun doAThingIfPresent(param1: Any?): String {
+        return (param1 as? String)?.let { doAThing(it) } ?: ""
+    }
+}
@@ -0,0 +1,12 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    val foo = maybeFoo()
+    if (null == foo<caret>)
+        bar
+    else
+        foo
+}
@@ -0,0 +1,8 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun main(args: Array<String>) {
+    val bar = "bar"
+    maybeFoo() ?: bar
+}
@@ -0,0 +1,13 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun bar(): String = "bar"
+
+fun main(args: Array<String>) {
+    val foo = maybeFoo()
+    if (null != foo<caret>)
+        foo
+    else
+        bar()
+}
@@ -0,0 +1,9 @@
+fun maybeFoo(): String? {
+    return "foo"
+}
+
+fun bar(): String = "bar"
+
+fun main(args: Array<String>) {
+    maybeFoo() ?: bar()
+}
@@ -0,0 +1,10 @@
+// PROBLEM: none
+fun main(args: Array<String>) {
+    val foo = null
+    if (foo == null<caret>) {
+        null
+    }
+    else {
+        null
+    }
+}
@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    val t: String? = "abc"
+    if (t != null<caret>) t else throw NullPointerException("'t' must not be null")
+}
@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun main(args: Array<String>) {
+    "abc" ?: throw NullPointerException("'t' must not be null")
+}
@@ -0,0 +1,16 @@
+// PROBLEM: none
+
+open class Some {
+    fun bar() {}
+}
+
+object Obj : Some()
+
+fun foo(arg: Any?) {
+    <caret>if (arg is Some) {
+        arg.bar()
+    }
+    else {
+        Obj.bar()
+    }
+}
@@ -0,0 +1,8 @@
+class F(a: Int?) {
+    val b = a
+    val c = if (b !=<caret> null) b else 2
+}
+
+fun main(args: Array<String>) {
+    F(1).c
+}
@@ -0,0 +1,8 @@
+class F(a: Int?) {
+    val b = a
+    val c = b ?: 2
+}
+
+fun main(args: Array<String>) {
+    F(1).c
+}
				`@@ -0,0 +1 @@`
				`org.jetbrains.kotlin.idea.inspections.branchedTransformations.IfThenToElvisInspection`