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Jakub Zawadzki
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Strings cannot be nil inspection
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13 files changed

+219
-0
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13 files changed

+219
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‎resources/META-INF/gogland.xml

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<localInspection language="go" displayName="Multiple packages in directory declaration" groupPath="Go"
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groupName="General" enabledByDefault="true" level="ERROR"
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implementationClass="com.goide.inspections.GoMultiplePackagesInspection"/>
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<localInspection language="go" displayName="String cannot be nil" groupPath="Go"
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groupName="General" enabledByDefault="true" level="ERROR"
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implementationClass="com.goide.inspections.GoStringCannotBeNilInspection"/>
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<localInspection language="go" displayName="Usage of cgo in tests is not supported" groupPath="Go"
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groupName="General" enabledByDefault="true" level="ERROR"
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implementationClass="com.goide.inspections.GoCgoInTestInspection"/>

‎resources/inspectionDescriptions/GoStringCannotBeNil.html

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<!--
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~ Copyright 2013-2017 Sergey Ignatov, Alexander Zolotov, Florin Patan
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~
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~ Licensed under the Apache License, Version 2.0 (the "License");
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~ you may not use this file except in compliance with the License.
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~ You may obtain a copy of the License at
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~
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~ http://www.apache.org/licenses/LICENSE-2.0
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~
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~ Unless required by applicable law or agreed to in writing, software
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~ distributed under the License is distributed on an "AS IS" BASIS,
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~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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~ See the License for the specific language governing permissions and
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~ limitations under the License.
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-->
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<html>
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<body>
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Inspects for string assignation or comparision to nil.
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</body>
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</html>

‎src/com/goide/inspections/GoStringCannotBeNilInspection.java

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package com.goide.inspections;
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import com.goide.GoConstants;
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import com.goide.GoTypes;
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import com.goide.psi.*;
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import com.goide.psi.impl.GoElementFactory;
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import com.goide.psi.impl.GoPsiImplUtil;
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import com.goide.psi.impl.GoTypeUtil;
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import com.intellij.codeInspection.*;
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import com.intellij.openapi.project.Project;
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import com.intellij.psi.PsiElement;
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import com.intellij.psi.tree.IElementType;
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import org.jetbrains.annotations.NotNull;
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import java.util.List;
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import java.util.stream.IntStream;
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public class GoStringCannotBeNilInspection extends GoInspectionBase {
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public static final String QUICK_FIX_NAME = "Change to default value";
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private static final String DEFAULT_STRING = "\"\"";
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private static final String PROBLEM_DESCRIPTION = "String cannot be nil";
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@NotNull
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@Override
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protected GoVisitor buildGoVisitor(@NotNull ProblemsHolder holder, @NotNull LocalInspectionToolSession session) {
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return new GoVisitor() {
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@Override
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public void visitVarSpec(@NotNull GoVarSpec o) {
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super.visitVarSpec(o);
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if (o.getVarDefinitionList() == null) return;
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o.getVarDefinitionList().forEach(var -> check(var, var != null ? var.getValue() : null));
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}
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@Override
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public void visitAssignmentStatement(@NotNull GoAssignmentStatement o) {
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super.visitAssignmentStatement(o);
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if (o.getLeftHandExprList() == null) return;
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List<GoExpression> rightSide = o.getExpressionList();
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List<GoExpression> leftSide = o.getLeftHandExprList().getExpressionList();
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if (leftSide == null || rightSide == null) return;
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IntStream.range(0, Math.min(leftSide.size(), rightSide.size()))
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.forEach(i -> check(leftSide.get(i), rightSide.get(i)));
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}
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@Override
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public void visitBinaryExpr(@NotNull GoBinaryExpr o) {
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super.visitBinaryExpr(o);
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if (o.getOperator() == null || o.getOperator().getNode() == null) return;
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IElementType type = o.getOperator().getNode().getElementType();
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if (type == GoTypes.EQ || type == GoTypes.NOT_EQ) {
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check(o.getLeft(), o.getRight());
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check(o.getRight(), o.getLeft());
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}
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}
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protected void check(GoTypeOwner var, GoExpression value) {
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if (var == null || value == null) return;
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GoType varType = var.getGoType(null);
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if (!GoTypeUtil.isString(varType)) return;
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if (value instanceof GoReferenceExpression && value.textMatches(GoConstants.NIL)
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&& GoPsiImplUtil.builtin(((GoReferenceExpression)value).resolve())) {
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holder.registerProblem(value, PROBLEM_DESCRIPTION, ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
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new GoChangeStringToDefaultValueQuickFix());
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}
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}
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};
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}
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private static class GoChangeStringToDefaultValueQuickFix extends LocalQuickFixBase {
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public GoChangeStringToDefaultValueQuickFix() {
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super(QUICK_FIX_NAME);
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}
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@Override
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public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
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PsiElement element = descriptor.getPsiElement();
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if (element == null || !element.isValid()) return;
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if (element instanceof GoExpression) {
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element.replace(GoElementFactory.createExpression(project, DEFAULT_STRING));
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}
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}
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}
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}

‎testData/inspections/string-assigned-to-nil/assignment-after.go

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package main
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func main() {
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var var1, var2, var3 string;
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var1, var2, var3 = "nil", "", "text"
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}

‎testData/inspections/string-assigned-to-nil/assignment.go

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package main
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func main() {
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var var1, var2, var3 string;
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var1, var2, var3 = "nil", <error descr="String cannot be nil"><caret>nil</error>, "text"
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}

‎testData/inspections/string-assigned-to-nil/comparison-after.go

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package main
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func main() {
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var var1 string;
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"" == var1
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}

‎testData/inspections/string-assigned-to-nil/comparison.go

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package main
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func main() {
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var var1 string;
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<error descr="String cannot be nil"><caret>nil</error> == var1
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}

‎testData/inspections/string-assigned-to-nil/nilVariable.go

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package main
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func main() {
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nil := "text"
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var1 := nil
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}

‎testData/inspections/string-assigned-to-nil/tooManyValues-after.go

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package main
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func main() {
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var var1, var2 string = "nil", "", 5 + 13
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}

‎testData/inspections/string-assigned-to-nil/tooManyValues.go

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package main
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func main() {
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var var1, var2 string = "nil", <error descr="String cannot be nil"><caret>nil</error>, 5 + 13
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}

‎testData/inspections/string-assigned-to-nil/varDeclaration-after.go

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package main
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func main() {
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var var1, var2, var3, var4 string = "nil", "", 5 + 13
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}

‎testData/inspections/string-assigned-to-nil/varDeclaration.go

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package main
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func main() {
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var var1, var2, var3, var4 string = "nil", <error descr="String cannot be nil"><caret>nil</error>, 5 + 13
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}

‎tests/com/goide/inspections/GoStringCannotBeNilInspectionTest.java

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/*
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* Copyright 2013-2017 Sergey Ignatov, Alexander Zolotov, Florin Patan
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.goide.inspections;
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import com.goide.SdkAware;
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import com.goide.quickfix.GoQuickFixTestBase;
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@SdkAware
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public class GoStringCannotBeNilInspectionTest extends GoQuickFixTestBase {
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@Override
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protected void setUp() throws Exception {
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super.setUp();
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myFixture.enableInspections(GoStringCannotBeNilInspection.class);
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}
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public void testVarDeclaration() {
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doTest(GoStringCannotBeNilInspection.QUICK_FIX_NAME, true);
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}
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public void testAssignment() {
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doTest(GoStringCannotBeNilInspection.QUICK_FIX_NAME, true);
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}
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public void testTooManyValues() {
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doTest(GoStringCannotBeNilInspection.QUICK_FIX_NAME, true);
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}
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public void testComparison() {
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doTest(GoStringCannotBeNilInspection.QUICK_FIX_NAME, true);
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}
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public void testNilVariable() {
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myFixture.testHighlighting(getTestName(true) + ".go");
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}
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@Override
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protected String getBasePath() {
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return "inspections/string-assigned-to-nil";
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}
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}

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