lumiera_/tests/library/diff/diff-tree-application-test.cpp
2025-06-07 23:59:57 +02:00

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/*
DiffTreeApplication(Test) - demonstrate the main features of tree diff representation
Copyright (C)
2015, 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 diff-tree-application-test.cpp
** unit test \ref DiffTreeApplication_test.
** Demonstrates the most relevant operations for reshaping structured data
** through a tree-diff sequence. Here, we use a lib::diff:Record<GenNode>
** as target data, and the test focuses on demonstrating the possible operations.
** @see [Introductory demonstration](\ref diff-tree-application-simple-test.cpp)
** @see [More complex setup with opaque data](\ref diff-complex-application-test.cpp)
*/
#include "lib/test/run.hpp"
#include "lib/format-util.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 lib::iter_stl::snapshot;
using util::isnil;
using util::join;
using std::string;
using std::vector;
using lib::time::Time;
namespace lib {
namespace diff{
namespace test{
namespace {//Test fixture....
// 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 Demonstration/Concept: a description language for tree differences.
* The representation is given as a linearised sequence of verb tokens.
* In addition to the verbs used for list diffing, here we additionally
* have to deal with nested scopes, which can be entered thorough a
* bracketing construct \c mut(ID)...emu(ID).
* This test demonstrates the application of such diff sequences
* - in the first step, an empty root #Record<GenNode> is populated
* with a type-ID, three named attribute values, three child values
* and a nested child-Record.
* - the second step demonstrates various diff language constructs
* to alter, reshape and mutate this data structure
* After applying those two diff sequences, we verify that
* the mutated data is indeed in the reordered shape.
* @remarks to follow this test, you should be familiar both with our
* [generic data record](\ref diff::Record), as well as with the
* [variant data node](\ref diff::GenNode). The key point to note
* is the usage of Record elements as payload within GenNode, which
* allows to represent tree shaped object-like data structures.
* @note literally the same test case is repeated in MutationMessage_test,
* just there the diff is transported in a MutationMessage capsule,
* as would be the case in the real application.
* @see DiffComplexApplication_test handling arbitrary data structures
* @see DiffTreeApplicationSimple_test introductory example demonstration
* @see GenericRecord_test
* @see GenNode_test
* @see DiffListApplication_test
* @see diff-tree-application.hpp
* @see tree-diff.hpp
*/
class DiffTreeApplication_test
: public Test
, TreeDiffLanguage
{
using DiffSeq = iter_stl::IterSnapshot<DiffStep>;
DiffSeq
populationDiff()
{
return snapshot({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)
});
}
DiffSeq
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 snapshot({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)
});
}
virtual void
run (Arg)
{
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 (DiffTreeApplication_test, "unit common");
}}} // namespace lib::diff::test