database_test.go

package golog

import . "github.com/mndrix/golog/term"

import "github.com/mndrix/golog/read"

import "testing"

func TestAsserta(t *testing.T) {
	db0 := NewDatabase()
	db1 := db0.Asserta(NewAtom("alpha"))
	db2 := db1.Asserta(NewAtom("beta"))

	db3 := db2.Asserta(read.Term_(`foo(one,two) :- alpha.`))
	t.Logf(db3.String()) // helpful for debugging

	// do we have the right number of clauses?
	if db0.ClauseCount() != 0 {
		t.Errorf("db0: wrong number of clauses: %d", db0.ClauseCount())
	}
	if db1.ClauseCount() != 1 {
		t.Errorf("db0: wrong number of clauses: %d", db0.ClauseCount())
	}
	if db2.ClauseCount() != 2 {
		t.Errorf("db0: wrong number of clauses: %d", db0.ClauseCount())
	}
	if db3.ClauseCount() != 3 {
		t.Errorf("db0: wrong number of clauses: %d", db0.ClauseCount())
	}

	// is alpha/0 present where it should be?
	if cs := db1.Candidates_(NewAtom("alpha")); len(cs) != 1 {
		t.Errorf("db1: can't find alpha/0")
	}
	if cs := db2.Candidates_(NewAtom("alpha")); len(cs) != 1 {
		t.Errorf("db2: can't find alpha/0")
	}
	if cs := db3.Candidates_(NewAtom("alpha")); len(cs) != 1 {
		t.Errorf("db3: can't find alpha/0")
	}

	// is beta/0 present where it should be?
	if _, err := db1.Candidates(NewAtom("beta")); err == nil {
		t.Errorf("db1: shouldn't have found beta/0")
	}
	if cs := db2.Candidates_(NewAtom("beta")); len(cs) != 1 {
		t.Errorf("db2: can't find beta/0")
	}
	if cs := db3.Candidates_(NewAtom("beta")); len(cs) != 1 {
		t.Errorf("db3: can't find beta/0")
	}

	// is foo/2 present where it should be?
	term := read.Term_(`foo(one,two).`)
	if _, err := db1.Candidates(term); err == nil {
		t.Errorf("db1: shouldn't have found foo/2")
	}
	if _, err := db2.Candidates(term); err == nil {
		t.Errorf("db2: shouldn't have found foo/2")
	}
	if cs := db3.Candidates_(term); len(cs) != 1 {
		t.Errorf("db3: can't find foo/2")
	}
}