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ExpectedExceptionToAssertThrows: Handle branching and var usage in except methods #721

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293 changes: 136 additions & 157 deletions src/main/java/org/openrewrite/java/testing/junit5/ExpectedExceptionToAssertThrows.java
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Original file line number Diff line number Diff line change
Expand Up @@ -15,20 +15,25 @@
*/
package org.openrewrite.java.testing.junit5;

import org.openrewrite.ExecutionContext;
import org.openrewrite.Preconditions;
import org.openrewrite.Recipe;
import org.openrewrite.TreeVisitor;
import org.openrewrite.*;
import org.openrewrite.internal.ListUtils;
import org.openrewrite.java.JavaIsoVisitor;
import org.openrewrite.java.JavaParser;
import org.openrewrite.java.JavaTemplate;
import org.openrewrite.java.MethodMatcher;
import org.openrewrite.java.search.UsesType;
import org.openrewrite.java.tree.*;
import org.openrewrite.marker.Markers;
import org.openrewrite.staticanalysis.LambdaBlockToExpression;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicBoolean;

import static java.util.Collections.emptyList;
import static org.openrewrite.Tree.randomId;

/**
* Replace usages of JUnit 4's @Rule ExpectedException with JUnit 5 Assertions.
Expand Down Expand Up @@ -61,6 +66,18 @@ public TreeVisitor<?, ExecutionContext> getVisitor() {

private static class ExpectedExceptionToAssertThrowsVisitor extends JavaIsoVisitor<ExecutionContext> {

private static final String FIRST_EXPECTED_EXCEPTION_METHOD_INVOCATION = "firstExpectedExceptionMethodInvocation";
private static final String STATEMENTS_AFTER_EXPECT_EXCEPTION = "statementsAfterExpectException";
private static final String HAS_MATCHER = "hasMatcher";
private static final String EXCEPTION_CLASS = "exceptionClass";

private static final MethodMatcher EXPECTED_EXCEPTION_ALL_MATCHER = new MethodMatcher("org.junit.rules.ExpectedException expect*(..)");
private static final MethodMatcher EXPECTED_EXCEPTION_CLASS_MATCHER = new MethodMatcher("org.junit.rules.ExpectedException expect(java.lang.Class)");
private static final MethodMatcher EXPECTED_MESSAGE_STRING_MATCHER = new MethodMatcher("org.junit.rules.ExpectedException expectMessage(java.lang.String)");
private static final MethodMatcher EXPECTED_MESSAGE_MATCHER = new MethodMatcher("org.junit.rules.ExpectedException expectMessage(org.hamcrest.Matcher)");
private static final MethodMatcher EXPECTED_EXCEPTION_MATCHER = new MethodMatcher("org.junit.rules.ExpectedException expect(org.hamcrest.Matcher)");
private static final MethodMatcher EXPECTED_EXCEPTION_CAUSE_MATCHER = new MethodMatcher("org.junit.rules.ExpectedException expectCause(org.hamcrest.Matcher)");

@Override
public J.ClassDeclaration visitClassDeclaration(J.ClassDeclaration classDecl, ExecutionContext ctx) {
J.ClassDeclaration cd = super.visitClassDeclaration(classDecl, ctx);
Expand All @@ -77,192 +94,154 @@ public J.ClassDeclaration visitClassDeclaration(J.ClassDeclaration classDecl, Ex
}
return statement;
})));

doAfterVisit(new LambdaBlockToExpression().getVisitor());
return cd;
}

@Override
public J.MethodDeclaration visitMethodDeclaration(J.MethodDeclaration methodDecl, ExecutionContext ctx) {
J.MethodDeclaration m = super.visitMethodDeclaration(methodDecl, ctx);

J.MethodInvocation expectMethodInvocation = getCursor().pollMessage("expectedExceptionMethodInvocation");
J.MethodInvocation expectMessageMethodInvocation = getCursor().pollMessage("expectedExceptionMethodMessageInvocation");
J.MethodInvocation expectCauseMethodInvocation = getCursor().pollMessage("expectCauseMethodInvocation");

if (expectMethodInvocation == null &&
expectMessageMethodInvocation == null &&
expectCauseMethodInvocation == null) {
return m;
}

assert m.getBody() != null;
J.Block bodyWithoutExpectedExceptionCalls = m.getBody().withStatements(ListUtils.map(m.getBody().getStatements(),
statement -> isExpectedExceptionMethodInvocation(statement) ? null : statement));

boolean isExpectArgAMatcher = false;
if (expectMethodInvocation != null) {
List<Expression> args = expectMethodInvocation.getArguments();
if (args.size() != 1) {
return m;
}

Expression expectMethodArg = args.get(0);
isExpectArgAMatcher = isHamcrestMatcher(expectMethodArg);
JavaType.FullyQualified argType = TypeUtils.asFullyQualified(expectMethodArg.getType());
if (!isExpectArgAMatcher && (argType == null || !"java.lang.Class".equals(argType.getFullyQualifiedName()))) {
return m;
public J.MethodDeclaration visitMethodDeclaration(J.MethodDeclaration method, ExecutionContext ctx) {
J.MethodDeclaration m = super.visitMethodDeclaration(method, ctx);
if (getCursor().pollMessage("hasExpectException") != null) {
List<NameTree> thrown = m.getThrows();
if (thrown != null && !thrown.isEmpty()) {
assert m.getBody() != null;
return m.withBody(m.getBody().withPrefix(thrown.get(0).getPrefix())).withThrows(Collections.emptyList());
}
}
return m;
}

boolean isExpectMessageArgAMatcher = false;
if (expectMessageMethodInvocation != null) {
List<Expression> args = expectMessageMethodInvocation.getArguments();
if (args.size() != 1) {
return m;
}

final Expression expectMessageMethodArg = args.get(0);
isExpectMessageArgAMatcher = isHamcrestMatcher(expectMessageMethodArg);
if (!isExpectMessageArgAMatcher && !TypeUtils.isString(expectMessageMethodArg.getType())) {
return m;
}
@Override
public J.Block visitBlock(J.Block block, ExecutionContext ctx) {
J.Block b = super.visitBlock(block, ctx);
List<Statement> statementsAfterExpectException = getCursor().pollMessage(STATEMENTS_AFTER_EXPECT_EXCEPTION);
if (statementsAfterExpectException == null) {
return b;
}

boolean isExpectedCauseArgAMatcher = false;
if (expectCauseMethodInvocation != null) {
List<Expression> args = expectCauseMethodInvocation.getArguments();
if (args.size() != 1) {
return m;
}

final Expression expectCauseMethodArg = args.get(0);
isExpectedCauseArgAMatcher = isHamcrestMatcher(expectCauseMethodArg);
if (!isExpectedCauseArgAMatcher) {
return m;
}
J.Block statementsAfterExpectExceptionBlock = new J.Block(randomId(), Space.EMPTY,
Markers.EMPTY, new JRightPadded<>(false, Space.EMPTY, Markers.EMPTY),
emptyList(), Space.format(" ")).withStatements(statementsAfterExpectException);
String exceptionDeclParam = getCursor().pollMessage(HAS_MATCHER) != null ? "Throwable exception = " : "";
Object exceptionClass = getCursor().pollMessage(EXCEPTION_CLASS);
if (exceptionClass == null) {
exceptionClass = "Exception.class";
}

String exceptionDeclParam = ((isExpectArgAMatcher || isExpectMessageArgAMatcher || isExpectedCauseArgAMatcher) ||
expectMessageMethodInvocation != null) ?
"Throwable exception = " : "";

Object expectedExceptionParam = (expectMethodInvocation == null || isExpectArgAMatcher) ?
"Exception.class" : expectMethodInvocation.getArguments().get(0);

String templateString = expectedExceptionParam instanceof String ? "#{}assertThrows(#{}, () -> #{any()});" : "#{}assertThrows(#{any()}, () -> #{any()});";
m = JavaTemplate.builder(templateString)
maybeAddImport("org.junit.jupiter.api.Assertions", "assertThrows", false);
Statement firstExpectedExceptionMethodInvocation = getCursor().getMessage(FIRST_EXPECTED_EXCEPTION_METHOD_INVOCATION);
String templateString = exceptionClass instanceof String ? "#{}assertThrows(#{}, () -> #{any()});" : "#{}assertThrows(#{any()}, () -> #{any()});";
b = JavaTemplate.builder(templateString)
.contextSensitive()
.javaParser(JavaParser.fromJavaVersion()
.classpathFromResources(ctx, "junit-jupiter-api-5", "hamcrest-3"))
.staticImports("org.junit.jupiter.api.Assertions.assertThrows")
.build()
.apply(
updateCursor(m),
m.getCoordinates().replaceBody(),
updateCursor(b),
firstExpectedExceptionMethodInvocation.getCoordinates().before(),
exceptionDeclParam,
expectedExceptionParam,
bodyWithoutExpectedExceptionCalls
exceptionClass,
statementsAfterExpectExceptionBlock
);

// Clear out any declared thrown exceptions
List<NameTree> thrown = m.getThrows();
if (thrown != null && !thrown.isEmpty()) {
assert m.getBody() != null;
m = m.withBody(m.getBody().withPrefix(thrown.get(0).getPrefix())).withThrows(Collections.emptyList());
}

// Unconditionally add the import for assertThrows, got a report where the above template adds the method successfully
// but with missing type attribution for assertThrows so the import was missing
maybeAddImport("org.junit.jupiter.api.Assertions", "assertThrows", false);

if (expectMessageMethodInvocation != null && !isExpectMessageArgAMatcher && m.getBody() != null) {
m = JavaTemplate.builder("assertTrue(exception.getMessage().contains(#{any(java.lang.String)}));")
.contextSensitive()
.javaParser(JavaParser.fromJavaVersion()
.classpathFromResources(ctx, "junit-jupiter-api-5", "hamcrest-3"))
.staticImports("org.junit.jupiter.api.Assertions.assertTrue")
.build()
.apply(
updateCursor(m),
m.getBody().getCoordinates().lastStatement(),
expectMessageMethodInvocation.getArguments().get(0)
);
maybeAddImport("org.junit.jupiter.api.Assertions", "assertTrue");
}

JavaTemplate assertThatTemplate = JavaTemplate.builder("assertThat(#{}, #{any()});")
.contextSensitive()
.javaParser(JavaParser.fromJavaVersion()
.classpathFromResources(ctx, "junit-jupiter-api-5", "hamcrest-3"))
.staticImports("org.hamcrest.MatcherAssert.assertThat")
.build();

assert m.getBody() != null;
if (isExpectArgAMatcher) {
m = assertThatTemplate.apply(updateCursor(m), m.getBody().getCoordinates().lastStatement(),
"exception", expectMethodInvocation.getArguments().get(0));
maybeAddImport("org.hamcrest.MatcherAssert", "assertThat");
}

assert m.getBody() != null;
if (isExpectMessageArgAMatcher) {
m = assertThatTemplate.apply(updateCursor(m), m.getBody().getCoordinates().lastStatement(),
"exception.getMessage()", expectMessageMethodInvocation.getArguments().get(0));
maybeAddImport("org.hamcrest.MatcherAssert", "assertThat");
}

assert m.getBody() != null;
if (isExpectedCauseArgAMatcher) {
m = assertThatTemplate.apply(updateCursor(m), m.getBody().getCoordinates().lastStatement(),
"exception.getCause()", expectCauseMethodInvocation.getArguments().get(0));
maybeAddImport("org.hamcrest.MatcherAssert", "assertThat");
Cursor updateCursor = updateCursor(b);
AtomicBoolean removeStatement = new AtomicBoolean(false);
J.Identifier exceptionIdentifier = new J.Identifier(Tree.randomId(),
Space.EMPTY,
Markers.EMPTY,
emptyList(),
"exception",
JavaType.ShallowClass.build("java.lang.Throwable"),
null);
b = b.withStatements(ListUtils.map(b.getStatements(), statement -> {
if (statement instanceof J.MethodInvocation) {
if (EXPECTED_EXCEPTION_ALL_MATCHER.matches((J.MethodInvocation) statement)) {
removeStatement.set(true);
return getExpectExceptionTemplate((J.MethodInvocation) statement, ctx)
.<J.MethodInvocation>map(t -> t.apply(
new Cursor(updateCursor, statement),
statement.getCoordinates().replace(), exceptionIdentifier,
((J.MethodInvocation) statement).getArguments().get(0)))
.orElse(null);
}
}
return removeStatement.get() ? null : statement;
}));
Statement lastStatement = b.getStatements().get(b.getStatements().size() - 1);
if (!findSuccessorStatements(new Cursor(updateCursor(b), lastStatement)).isEmpty()) {
J.Return returnStatement = new J.Return(randomId(), b.getStatements().get(b.getStatements().size() - 1).getPrefix().withComments(emptyList()), Markers.EMPTY, null);
return b.withStatements(ListUtils.concat(b.getStatements(), returnStatement));
}

doAfterVisit(new LambdaBlockToExpression().getVisitor());

return m;
return b;
}

@Override
public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
if (method.getMethodType() != null && "org.junit.rules.ExpectedException".equals(method.getMethodType().getDeclaringType().getFullyQualifiedName())) {
switch (method.getSimpleName()) {
case "expect":
getCursor().putMessageOnFirstEnclosing(J.MethodDeclaration.class, "expectedExceptionMethodInvocation", method);
break;
case "expectMessage":
getCursor().putMessageOnFirstEnclosing(J.MethodDeclaration.class, "expectedExceptionMethodMessageInvocation", method);
break;
case "expectCause":
getCursor().putMessageOnFirstEnclosing(J.MethodDeclaration.class, "expectCauseMethodInvocation", method);
break;
}
if (!EXPECTED_EXCEPTION_ALL_MATCHER.matches(method)) {
return method;
}
getCursor().dropParentUntil(J.MethodDeclaration.class::isInstance).putMessage("hasExpectException", true );
getCursor().dropParentUntil(J.Block.class::isInstance).computeMessageIfAbsent(FIRST_EXPECTED_EXCEPTION_METHOD_INVOCATION, k -> method);
List<Statement> successorStatements = findSuccessorStatements(getCursor());
getCursor().putMessageOnFirstEnclosing(J.Block.class, STATEMENTS_AFTER_EXPECT_EXCEPTION, successorStatements);
if (EXPECTED_EXCEPTION_CLASS_MATCHER.matches(method)) {
getCursor().putMessageOnFirstEnclosing(J.Block.class, EXCEPTION_CLASS, method.getArguments().get(0));
} else {
getCursor().putMessageOnFirstEnclosing(J.Block.class, HAS_MATCHER, true);
}
return method;
}

private boolean isHamcrestMatcher(J j) {
if (!(j instanceof J.MethodInvocation)) {
return false;
/**
* From the current cursor point find all the next statements that can be executed in the current path.
*/
private List<Statement> findSuccessorStatements(Cursor cursor) {
if (cursor.firstEnclosing(J.MethodDeclaration.class) == null) {
return Collections.emptyList();
}

final J.MethodInvocation method = (J.MethodInvocation) j;
return method.getArguments().size() == 1 &&
method.getMethodType() != null &&
TypeUtils.isOfClassType(method.getMethodType().getDeclaringType(), "org.hamcrest.Matchers");
List<Statement> successorStatements = new ArrayList<>();
Cursor cursorJustBeforeBlock = getCursor();
while (!(cursor.getValue() instanceof J.MethodDeclaration)) {
if (!(cursor.getValue() instanceof J.Block)) {
cursorJustBeforeBlock = cursor;
cursor = cursor.getParentTreeCursor();
continue;
}
J.Block block = cursor.getValue();
boolean found = false;
for (Statement statement : block.getStatements()) {
if (found) {
successorStatements.add(statement);
} else if (statement == cursorJustBeforeBlock.getValue()) {
found = true;
}
}
cursor = cursor.getParentTreeCursor();
}
return successorStatements;
}

private static boolean isExpectedExceptionMethodInvocation(Statement statement) {
if (!(statement instanceof J.MethodInvocation)) {
return false;
private Optional<JavaTemplate> getExpectExceptionTemplate(J.MethodInvocation method, ExecutionContext ctx) {
String template = null;
if (EXPECTED_MESSAGE_STRING_MATCHER.matches(method)) {
maybeAddImport("org.hamcrest.CoreMatchers", "containsString");
template = "assertThat(#{any(java.lang.Throwable)}.getMessage(), containsString(#{any(java.lang.String)}))";
} else if (EXPECTED_MESSAGE_MATCHER.matches(method)) {
template = "assertThat(#{any(java.lang.Throwable)}.getMessage(), #{any(org.hamcrest.Matcher)})";
} else if (EXPECTED_EXCEPTION_MATCHER.matches(method)) {
template = "assertThat(#{any(java.lang.Throwable)}, #{any(org.hamcrest.Matcher)})";
} else if (EXPECTED_EXCEPTION_CAUSE_MATCHER.matches(method)) {
template = "assertThat(#{any(java.lang.Throwable)}.getCause(), #{any(org.hamcrest.Matcher)})";
}

J.MethodInvocation m = (J.MethodInvocation) statement;
if (m.getMethodType() == null) {
return false;
if (template == null) {
return Optional.empty();
}
maybeAddImport("org.hamcrest.MatcherAssert", "assertThat");
return Optional.of(JavaTemplate.builder(template).contextSensitive()
.javaParser(JavaParser.fromJavaVersion()
.classpathFromResources(ctx, "junit-jupiter-api-5", "hamcrest-3"))
.staticImports("org.hamcrest.MatcherAssert.assertThat", "org.hamcrest.CoreMatchers.containsString")
.build());

return TypeUtils.isOfClassType(m.getMethodType().getDeclaringType(), "org.junit.rules.ExpectedException");
}
}
}
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