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+# FIR Analysis tests
+
+Mostly, format of FIR analysis test is the same as the one described at `compiler/testData/diagnostics/ReadMe.md`.
+
+
+`DEBUG_INFO_EXPRESSION_TYPE` and `DEBUG_INFO_CALL` are also partially supported but need to be written out explicitly in a test data file:
+```kotlin
+fun foo(
+    x1: String,
+    x2: Collection<CharSequence>,
+    x3: MutableMap<out CharSequence, in MutableList<*>>
+) {
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String")!>x1<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.collections.Collection<kotlin.CharSequence>")!>x2<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.collections.MutableMap<out kotlin.CharSequence, in kotlin.collections.MutableList<*>>")!>x3<!>
+}
+
+interface B {
+    operator fun invoke(x: Int): String
+}
+
+class A {
+    fun foo(x: Int) {
+        fun baz(x: Double) {}
+        <!DEBUG_INFO_CALL("fqName: A.foo.baz; typeCall: function")!>baz(1.0)<!>
+    }
+
+    val bar: B = TODO()
+}
+
+fun A.foo(x: String) {}
+
+fun main() {
+    fun A.foo(x: Double) {}
+    val a = A()
+    a.<!DEBUG_INFO_CALL("fqName: A.foo; typeCall: function")!>foo(1)<!>
+    a.<!DEBUG_INFO_CALL("fqName: foo; typeCall: extension function")!>foo("")<!>
+    a.<!DEBUG_INFO_CALL("fqName: main.foo; typeCall: extension function")!>foo(1.0)<!>
+    a.<!DEBUG_INFO_CALL("fqName: B.invoke; typeCall: variable&invoke")!>bar(1)<!>
+}
+```
+
+## Specific Directives
+- `// FIR_IDENTICAL` should be prepended in a `.kt` file of an old diagnostic test when analysis result of old FE and FIR are the same
+- `// FIR_IGNORE` should be prepended in a `.fir.kt` file of an old diagnostic test known to fail with exception
+- `// !DUMP_CFG` generates `.dot` file with rendered data flow graph (see comment at `org.jetbrains.kotlin.fir.AbstractFirDiagnosticsTest`)