lumiera_/tests/library/diff/mutation-message-test.cpp
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/*
MutationMessage(Test) - verify diff mutation message container
Copyright (C)
2017, Hermann Vosseler <Ichthyostega@web.de>
  **Lumiera** is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version. See the file COPYING for further details.
* *****************************************************************/
/** @file mutation-message-test.cpp
** unit test \ref MutationMessage_test
*/
#include "lib/test/run.hpp"
#include "lib/test/test-helper.hpp"
#include "lib/diff/mutation-message.hpp"
#include "lib/diff/tree-diff-application.hpp"
#include "lib/iter-adapter-stl.hpp"
#include "lib/time/timevalue.hpp"
#include "lib/format-util.hpp"
#include "lib/util.hpp"
#include <string>
#include <vector>
using LERR_(ITER_EXHAUST);
using lib::iter_stl::IterSnapshot;
using lib::iter_stl::snapshot;
using lib::time::Time;
using util::contains;
using util::isnil;
using util::join;
using std::string;
using std::vector;
namespace lib {
namespace diff{
namespace test{
namespace {//Test fixture....
int instances = 0; ///< verify instance management
// define some GenNode elements
// to act as templates within the concrete diff
// NOTE: everything in this diff language is by-value
const GenNode ATTRIB1("α", 1), // attribute α = 1
ATTRIB2("β", int64_t(2)), // attribute α = 2L (int64_t)
ATTRIB3("γ", 3.45), // attribute γ = 3.45 (double)
TYPE_X("type", "X"), // a "magic" type attribute "X"
TYPE_Y("type", "Y"), //
CHILD_A("a"), // unnamed string child node
CHILD_B('b'), // unnamed char child node
CHILD_T(Time(12,34,56,78)), // unnamed time value child
SUB_NODE = MakeRec().genNode(), // empty anonymous node used to open a sub scope
ATTRIB_NODE = MakeRec().genNode("δ"), // empty named node to be attached as attribute δ
CHILD_NODE = SUB_NODE; // yet another child node, same ID as SUB_NODE (!)
}//(End)Test fixture
/***********************************************************************//**
* @test properties of a container to transport a diff from an abstracted
* source generator to an abstracted consumer.
* - this covers a standard usage scenario within Lumiera, where some
* producer in the Session core detects changes in session structure
* and sends a message to make the UI conform to the new structure
* - diff messages are hard to debug and test, since they are designed
* as opaque sequences to be consumed only once. Thus for we provide
* a snapshot decorator to offer diagnostic facilities
* - moreover we provide a simplified builder function to create
* hard wired diff messages in a concise way
* - and finally this test repeats the scenario of DiffTreeApplication_test,
* but this time the diff sequences are encapsulated as MutationMessage.
* @remarks like all the other _diff related_ tests, this code might be hard
* to follow, unless you're familiar with the underlying concepts. Basically,
* a _Diff_ is represented as _a linearised sequence of verb tokens_. Together
* these tokens form a _diff language_. The semantics of that language are
* oriented towards application of this diff onto a target structure. The
* goal is to represent structure changes without being bound to a specific
* data structure implementation. Yet there is one _meta_ data representation
* used within the diff itself, as well as for various test and demonstration
* examples: the [generic data record](\ref diff::Record) together with its
* [variant node element](\ref diff::GenNode). The key point to note is the
* (recursive) usage of Record elements as payload within GenNode, which
* allows to represent tree shaped object like data structures.
*
* @see AbstractTangible_test::mutate() concrete usage scenario for UI-elements
* @see DiffTreeApplication_test change a tree-like data structure by diff
* @see DiffComplexApplication_test handling arbitrary data structures
* @see DiffListApplication_test
* @see MutationMessage
* @see ui-bus.hpp
*/
class MutationMessage_test
: public Test
, TreeDiffLanguage
{
virtual void
run (Arg)
{
demonstrate_standardUsage();
verify_builder();
verify_diagnostics();
demonstrate_treeApplication();
}
/** @test demonstrate the intended usage pattern
* - a diff generation context is allocated
* - the MutationMessage takes ownership
* - and exposes the generated diff sequence
* - which is pulled during iteration
*/
void
demonstrate_standardUsage()
{
using Source = WrappedLumieraIter<IterSnapshot<DiffStep>>;
/* opaque generation context */
struct Generator
: TreeDiffLanguage
, Source
{
Generator()
: Source{snapshot({ins(TYPE_X)
,set(ATTRIB1)
,del(CHILD_T)})}
{
++instances;
}
~Generator()
{
--instances;
}
};
CHECK (0 == instances);
{
MutationMessage diffMsg{new Generator};
CHECK (!isnil (diffMsg));
CHECK (1 == instances);
CHECK (diffMsg);
CHECK (ins(TYPE_X) == *diffMsg);
// and this effectively means....
CHECK ("ins" == string(diffMsg->verb()));
CHECK ("type" == diffMsg->elm().idi.getSym());
CHECK ("X" == diffMsg->elm().data.get<string>());
// now iterate one step
++diffMsg;
CHECK (diffMsg);
CHECK (set(ATTRIB1) == *diffMsg);
CHECK ("set" == string(diffMsg->verb()));
CHECK ("α" == diffMsg->elm().idi.getSym());
CHECK ( 1 == diffMsg->elm().data.get<int>());
// cloning is allowed, yet implementation defined
// in the actual case the underlying generator is based on a vector + a pointer
// and thus the full state can be cloned into an independent instance
MutationMessage clone{diffMsg};
CHECK (clone == diffMsg);
CHECK (set(ATTRIB1) == *clone);
CHECK (1 == instances); // the iterator front-end was cloned, not the generator
++clone;
CHECK (del(CHILD_T) == *clone);
CHECK (set(ATTRIB1) == *diffMsg);
CHECK (clone != diffMsg);
++clone;
CHECK (not clone);
CHECK (isnil (clone));
VERIFY_ERROR(ITER_EXHAUST, *clone);
// note the weird behaviour:
// both instances share a common backend and thus state get mixed up.
// The diffMsg front-End still points at a state already obsoleted
CHECK (set(ATTRIB1) == *diffMsg);
++diffMsg;
// So better don't do this at home...
VERIFY_ERROR(ITER_EXHAUST, *diffMsg);
clone = MutationMessage{new Generator};
CHECK (2 == instances); // now we got two independent generator instances
CHECK (clone);
CHECK (ins(TYPE_X) == *clone);
++clone;
CHECK (set(ATTRIB1) == *clone);
// first instance unaffected as before
CHECK (isnil (diffMsg));
}// NOTE: automatic clean-up when leaving the scope
CHECK (0 == instances);
}
void
verify_builder()
{
MutationMessage diffMsg{ins(TYPE_X)
,set(ATTRIB1)
,del(CHILD_T)};
CHECK (!isnil (diffMsg));
CHECK (ins(TYPE_X) == *diffMsg);
CHECK (set(ATTRIB1) == *++diffMsg);
CHECK (del(CHILD_T) == *++diffMsg);
CHECK (isnil (++diffMsg));
VERIFY_ERROR(ITER_EXHAUST, *diffMsg);
// likewise works with a std::initializer_list
diffMsg = MutationMessage{{ins(TYPE_X)
,set(ATTRIB1)
,del(CHILD_T)}
};
CHECK (!isnil (diffMsg));
CHECK (ins(TYPE_X) == *diffMsg);
CHECK (set(ATTRIB1) == *++diffMsg);
CHECK (del(CHILD_T) == *++diffMsg);
CHECK (isnil (++diffMsg));
// even passing any suitable iterable works
diffMsg = MutationMessage{snapshot({ins(TYPE_X)
,set(ATTRIB1)
,del(CHILD_T)})
};
CHECK (!isnil (diffMsg));
CHECK (ins(TYPE_X) == *diffMsg);
CHECK (set(ATTRIB1) == *++diffMsg);
CHECK (del(CHILD_T) == *++diffMsg);
CHECK (isnil (++diffMsg));
// really anything iterable...
std::vector<DiffStep> steps;
CHECK (isnil (steps));
append_all(snapshot({ins(TYPE_X)
,set(ATTRIB1)
,del(CHILD_T)}), steps);
diffMsg = MutationMessage{steps};
CHECK (!isnil (diffMsg));
CHECK (ins(TYPE_X) == *diffMsg);
CHECK (set(ATTRIB1) == *++diffMsg);
CHECK (del(CHILD_T) == *++diffMsg);
CHECK (isnil (++diffMsg));
}
void
verify_diagnostics()
{
MutationMessage diffMsg{ins(TYPE_X)
,set(ATTRIB1)
,del(CHILD_T)};
// initially only the default diagnostics of IterSource is shown (rendering the element type)
CHECK (string(diffMsg) == "IterSource<DiffLanguage<TreeDiffInterpreter, GenNode>::DiffStep>");
// transparently take a snapshot
diffMsg.updateDiagnostics();
// now the whole sequence is rendered explicitly
string expectedRendering = join ({ins(TYPE_X), set(ATTRIB1), del(CHILD_T)});
CHECK (contains (string(diffMsg), expectedRendering));
CHECK (string(set(ATTRIB1)) == "set(GenNode-ID(\"α\")-DataCap|«int»|1)");
// and we can still iterate...
CHECK (!isnil (diffMsg));
CHECK (ins(TYPE_X) == *diffMsg);
CHECK (set(ATTRIB1) == *++diffMsg);
// NOTE: in fact only the remainder of the sequence is captured...
diffMsg.updateDiagnostics();
CHECK (not contains (string(diffMsg), string(ins(TYPE_X))));
CHECK ( contains (string(diffMsg), string(set(ATTRIB1))));
CHECK ( contains (string(diffMsg), string(del(CHILD_T))));
// and we can still continue to iterate...
CHECK (del(CHILD_T) == *++diffMsg);
CHECK (isnil (++diffMsg));
diffMsg.updateDiagnostics();
CHECK (string(diffMsg) == "Diff--{}");
}
MutationMessage
populationDiff()
{
return { ins(TYPE_X)
, ins(ATTRIB1)
, ins(ATTRIB2)
, ins(ATTRIB3)
, ins(CHILD_A)
, ins(CHILD_T)
, ins(CHILD_T)
, ins(SUB_NODE)
, mut(SUB_NODE)
, ins(CHILD_B)
, ins(CHILD_A)
, emu(SUB_NODE)
};
}
MutationMessage
mutationDiff()
{
// prepare for direct assignment of new value
// NOTE: the target ID will be reconstructed, including hash
GenNode childA_upper(CHILD_A.idi.getSym(), "A");
return { after(Ref::ATTRIBS) // fast forward to the first child
, find(CHILD_T)
, pick(CHILD_A)
, skip(CHILD_T)
, del(CHILD_T)
, after(Ref::END) // accept anything beyond as-is
, mut(SUB_NODE)
, ins(ATTRIB3)
, ins(ATTRIB_NODE) // attributes can also be nested objects
, find(CHILD_A)
, del(CHILD_B)
, ins(CHILD_NODE)
, ins(CHILD_T)
, skip(CHILD_A)
, mut(CHILD_NODE)
, ins(TYPE_Y)
, ins(ATTRIB2)
, emu(CHILD_NODE)
, set(childA_upper) // direct assignment, target found by ID (out of order)
, mut(ATTRIB_NODE) // mutation can be out-of order, target found by ID
, ins(CHILD_A)
, ins(CHILD_A)
, ins(CHILD_A)
, emu(ATTRIB_NODE)
, emu(SUB_NODE)
};
}
/** @test use MutationMessage to transport and apply changes to target data
* @remarks this almost literally repeats the DiffTreeApplication_test */
void
demonstrate_treeApplication()
{
Rec::Mutator target;
Rec& subject = target;
DiffApplicator<Rec::Mutator> application(target);
// Part I : apply diff to populate
application.consume (populationDiff());
CHECK (!isnil (subject)); // nonempty -- content has been added
CHECK ("X" == subject.getType()); // type was set to "X"
CHECK (1 == subject.get("α").data.get<int>()); // has gotten our int attribute "α"
CHECK (2L == subject.get("β").data.get<int64_t>()); // ... the long attribute "β"
CHECK (3.45 == subject.get("γ").data.get<double>()); // ... and double attribute "γ"
auto scope = subject.scope(); // look into the scope contents...
CHECK ( *scope == CHILD_A); // there is CHILD_A
CHECK (*++scope == CHILD_T); // followed by a copy of CHILD_T
CHECK (*++scope == CHILD_T); // and another copy of CHILD_T
CHECK (*++scope == MakeRec().appendChild(CHILD_B) // and there is a nested Record
.appendChild(CHILD_A) // with CHILD_B
.genNode(SUB_NODE.idi.getSym())); // and CHILD_A
CHECK (isnil(++scope)); // thats all -- no more children
// Part II : apply the second diff
application.consume (mutationDiff());
CHECK (join (subject.keys()) == "α, β, γ"); // the attributes weren't altered
scope = subject.scope(); // but the scope was reordered
CHECK ( *scope == CHILD_T); // CHILD_T
CHECK (*++scope == CHILD_A); // CHILD_A
Rec nested = (++scope)->data.get<Rec>(); // and our nested Record, which too has been altered:
CHECK (nested.get("γ").data.get<double>() == 3.45); // it carries now an attribute "δ", which is again
CHECK (nested.get("δ") == MakeRec().appendChild(CHILD_A) // a nested Record with three children CHILD_A
.appendChild(CHILD_A) //
.appendChild(CHILD_A) //
.genNode("δ")); //
auto subScope = nested.scope(); // and within the nested sub-scope we find
CHECK ( *subScope != CHILD_A); // CHILD_A has been altered by assignment
CHECK (CHILD_A.idi == subScope->idi); // ...: same ID as CHILD_A
CHECK ("A" == subScope->data.get<string>()); // ...: but mutated payload
CHECK (*++subScope == MakeRec().type("Y") // a yet-again nested sub-Record of type "Y"
.set("β", int64_t(2)) // with just an attribute "β" == 2L
.genNode(CHILD_NODE.idi.getSym())); // (and an empty child scope)
CHECK (*++subScope == CHILD_T); // followed by another copy of CHILD_T
CHECK (isnil (++subScope)); //
CHECK (isnil (++scope)); // and nothing beyond that.
}
};
/** Register this test class... */
LAUNCHER (MutationMessage_test, "unit common");
}}} // namespace lib::diff::test