Enhance test suite

INSTALL

@@ -30,7 +30,7 @@ like the GNU glibc.
 The threaded version of FORM needs a Posix compliant implementation of threads
 (pthreads). The parallel version ParFORM needs an MPI implementation.
 
-The automated test suite of FORM requires Ruby version >= 1.9 and the testing
+The automated test suite of FORM requires Ruby version >= 2.0 and the testing
 framework "test/unit". For the latter, you may need to install test-unit gem
 separately.
 
@@ -174,7 +174,7 @@ can be used.
 Testing
 =======
 
-If Ruby version >= 1.9 and "test/unit" are installed on your system, the
+If Ruby version >= 2.0 and "test/unit" are installed on your system, the
 configure script enables the automated test suite. Then you can run it by
 
     make check

check/.rubocop.yml

@@ -1,5 +1,9 @@
-# AllCops:
-#   TargetRubyVersion: 2.1
+AllCops:
+  TargetRubyVersion: 2.0
+
+# We learned to do multiplication before addition in school.
+Lint/AmbiguousOperatorPrecedence:
+  Enabled: false
 
 # Allow several expressions on the same line.
 Style/Semicolon:
@@ -30,6 +34,9 @@ Style/WhileUntilModifier:
 Style/NegatedIf:
   Enabled: false
 
+Style/NegatedIfElseCondition:
+  Enabled: false
+
 Style/NegatedWhile:
   Enabled: false
 
@@ -81,17 +88,251 @@ Metrics/PerceivedComplexity:
 
 # For now.
 
+Style/ClassVars:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
+
 Style/FormatStringToken:
   EnforcedStyle: unannotated
 
-Style/PerlBackrefs:
+Style/GlobalVars:
+  Enabled: false
+
+Style/OpenStructUse:
   Enabled: false
 
-Style/SlicingWithRange:  # OK only for Ruby 2.6+
+Style/PerlBackrefs:
   Enabled: false
 
 Style/SpecialGlobalVars:
   EnforcedStyle: use_perl_names
 
 Style/StderrPuts:
   Enabled: false
+
+#####
+
+# Enable all other cops.
+
+Gemspec/AddRuntimeDependency: # new in 1.65
+  Enabled: true
+Gemspec/DeprecatedAttributeAssignment: # new in 1.30
+  Enabled: true
+Gemspec/DevelopmentDependencies: # new in 1.44
+  Enabled: true
+Gemspec/RequireMFA: # new in 1.23
+  Enabled: true
+Layout/LineContinuationLeadingSpace: # new in 1.31
+  Enabled: true
+Layout/LineContinuationSpacing: # new in 1.31
+  Enabled: true
+Layout/LineEndStringConcatenationIndentation: # new in 1.18
+  Enabled: true
+Layout/SpaceBeforeBrackets: # new in 1.7
+  Enabled: true
+Lint/AmbiguousAssignment: # new in 1.7
+  Enabled: true
+Lint/AmbiguousRange: # new in 1.19
+  Enabled: true
+Lint/ConstantOverwrittenInRescue: # new in 1.31
+  Enabled: true
+Lint/DeprecatedConstants: # new in 1.8
+  Enabled: true
+Lint/DuplicateBranch: # new in 1.3
+  Enabled: true
+Lint/DuplicateMagicComment: # new in 1.37
+  Enabled: true
+Lint/DuplicateMatchPattern: # new in 1.50
+  Enabled: true
+Lint/DuplicateRegexpCharacterClassElement: # new in 1.1
+  Enabled: true
+Lint/DuplicateSetElement: # new in 1.67
+  Enabled: true
+Lint/EmptyBlock: # new in 1.1
+  Enabled: true
+Lint/EmptyClass: # new in 1.3
+  Enabled: true
+Lint/EmptyInPattern: # new in 1.16
+  Enabled: true
+Lint/IncompatibleIoSelectWithFiberScheduler: # new in 1.21
+  Enabled: true
+Lint/ItWithoutArgumentsInBlock: # new in 1.59
+  Enabled: true
+Lint/LambdaWithoutLiteralBlock: # new in 1.8
+  Enabled: true
+Lint/LiteralAssignmentInCondition: # new in 1.58
+  Enabled: true
+Lint/MixedCaseRange: # new in 1.53
+  Enabled: true
+Lint/NoReturnInBeginEndBlocks: # new in 1.2
+  Enabled: true
+Lint/NonAtomicFileOperation: # new in 1.31
+  Enabled: true
+Lint/NumberedParameterAssignment: # new in 1.9
+  Enabled: true
+Lint/OrAssignmentToConstant: # new in 1.9
+  Enabled: true
+Lint/RedundantDirGlobSort: # new in 1.8
+  Enabled: true
+Lint/RedundantRegexpQuantifiers: # new in 1.53
+  Enabled: true
+Lint/RefinementImportMethods: # new in 1.27
+  Enabled: true
+Lint/RequireRangeParentheses: # new in 1.32
+  Enabled: true
+Lint/RequireRelativeSelfPath: # new in 1.22
+  Enabled: true
+Lint/SymbolConversion: # new in 1.9
+  Enabled: true
+Lint/ToEnumArguments: # new in 1.1
+  Enabled: true
+Lint/TripleQuotes: # new in 1.9
+  Enabled: true
+Lint/UnescapedBracketInRegexp: # new in 1.68
+  Enabled: true
+Lint/UnexpectedBlockArity: # new in 1.5
+  Enabled: true
+Lint/UnmodifiedReduceAccumulator: # new in 1.1
+  Enabled: true
+Lint/UselessNumericOperation: # new in 1.66
+  Enabled: true
+Lint/UselessRescue: # new in 1.43
+  Enabled: true
+Lint/UselessRuby2Keywords: # new in 1.23
+  Enabled: true
+Metrics/CollectionLiteralLength: # new in 1.47
+  Enabled: true
+Naming/BlockForwarding: # new in 1.24
+  Enabled: true
+Security/CompoundHash: # new in 1.28
+  Enabled: true
+Security/IoMethods: # new in 1.22
+  Enabled: true
+Style/AmbiguousEndlessMethodDefinition: # new in 1.68
+  Enabled: true
+Style/ArgumentsForwarding: # new in 1.1
+  Enabled: true
+Style/ArrayIntersect: # new in 1.40
+  Enabled: true
+Style/BitwisePredicate: # new in 1.68
+  Enabled: true
+Style/CollectionCompact: # new in 1.2
+  Enabled: true
+Style/CombinableDefined: # new in 1.68
+  Enabled: true
+Style/ComparableClamp: # new in 1.44
+  Enabled: true
+Style/ConcatArrayLiterals: # new in 1.41
+  Enabled: true
+Style/DataInheritance: # new in 1.49
+  Enabled: true
+Style/DirEmpty: # new in 1.48
+  Enabled: true
+Style/DocumentDynamicEvalDefinition: # new in 1.1
+  Enabled: true
+Style/EmptyHeredoc: # new in 1.32
+  Enabled: true
+Style/EndlessMethod: # new in 1.8
+  Enabled: true
+Style/EnvHome: # new in 1.29
+  Enabled: true
+Style/ExactRegexpMatch: # new in 1.51
+  Enabled: true
+Style/FetchEnvVar: # new in 1.28
+  Enabled: true
+Style/FileEmpty: # new in 1.48
+  Enabled: true
+Style/FileRead: # new in 1.24
+  Enabled: true
+Style/FileWrite: # new in 1.24
+  Enabled: true
+Style/HashConversion: # new in 1.10
+  Enabled: true
+Style/HashExcept: # new in 1.7
+  Enabled: true
+Style/IfWithBooleanLiteralBranches: # new in 1.9
+  Enabled: true
+Style/InPatternThen: # new in 1.16
+  Enabled: true
+Style/KeywordArgumentsMerging: # new in 1.68
+  Enabled: true
+Style/MagicCommentFormat: # new in 1.35
+  Enabled: true
+Style/MapCompactWithConditionalBlock: # new in 1.30
+  Enabled: true
+Style/MapIntoArray: # new in 1.63
+  Enabled: true
+Style/MapToHash: # new in 1.24
+  Enabled: true
+Style/MapToSet: # new in 1.42
+  Enabled: true
+Style/MinMaxComparison: # new in 1.42
+  Enabled: true
+Style/MultilineInPatternThen: # new in 1.16
+  Enabled: true
+Style/NestedFileDirname: # new in 1.26
+  Enabled: true
+Style/NilLambda: # new in 1.3
+  Enabled: true
+Style/NumberedParameters: # new in 1.22
+  Enabled: true
+Style/NumberedParametersLimit: # new in 1.22
+  Enabled: true
+Style/ObjectThen: # new in 1.28
+  Enabled: true
+Style/OperatorMethodCall: # new in 1.37
+  Enabled: true
+Style/QuotedSymbols: # new in 1.16
+  Enabled: true
+Style/RedundantArgument: # new in 1.4
+  Enabled: true
+Style/RedundantArrayConstructor: # new in 1.52
+  Enabled: true
+Style/RedundantConstantBase: # new in 1.40
+  Enabled: true
+Style/RedundantCurrentDirectoryInPath: # new in 1.53
+  Enabled: true
+Style/RedundantDoubleSplatHashBraces: # new in 1.41
+  Enabled: true
+Style/RedundantEach: # new in 1.38
+  Enabled: true
+Style/RedundantFilterChain: # new in 1.52
+  Enabled: true
+Style/RedundantHeredocDelimiterQuotes: # new in 1.45
+  Enabled: true
+Style/RedundantInitialize: # new in 1.27
+  Enabled: true
+Style/RedundantInterpolationUnfreeze: # new in 1.66
+  Enabled: true
+Style/RedundantLineContinuation: # new in 1.49
+  Enabled: true
+Style/RedundantRegexpArgument: # new in 1.53
+  Enabled: true
+Style/RedundantRegexpConstructor: # new in 1.52
+  Enabled: true
+Style/RedundantSelfAssignmentBranch: # new in 1.19
+  Enabled: true
+Style/RedundantStringEscape: # new in 1.37
+  Enabled: true
+Style/ReturnNilInPredicateMethodDefinition: # new in 1.53
+  Enabled: true
+Style/SafeNavigationChainLength: # new in 1.68
+  Enabled: true
+Style/SelectByRegexp: # new in 1.22
+  Enabled: true
+Style/SendWithLiteralMethodName: # new in 1.64
+  Enabled: true
+Style/SingleLineDoEndBlock: # new in 1.57
+  Enabled: true
+Style/StringChars: # new in 1.12
+  Enabled: true
+Style/SuperArguments: # new in 1.64
+  Enabled: true
+Style/SuperWithArgsParentheses: # new in 1.58
+  Enabled: true
+Style/SwapValues: # new in 1.1
+  Enabled: true
+Style/YAMLFileRead: # new in 1.53
+  Enabled: true