/* Tests for libfossil/th1ish delta generation and application... */
scope {/* just to get some UTF8 in here for diff validation */
// If any of these assertions fail then this file is not UTF8-encoded
assert "®" === [["®".charAt 0 true].toUtf8Char]
assert "®" === [["©®".charAt 1 true].toUtf8Char]
assert "®" === "©®".charAt(1,true).toUtf8Char()
assert "ä" === "äbä".substr(0,1)
assert "©" === "äb©®ä".substr(2,1)
assert "©®" === "äb©®ä".substr(2,2)
}
scope {
// The base content we want to delta against...
const inFile = __FILE
const inSize = [Fossil.file.size inFile]
const b = [api.Buffer inSize+1]
[b.readFile inFile]
[print "Input file: " inFile ", size=" inSize]
const bStr = [b.toString]
// Make a modified copy of the original...
//const c = [clone b] //[api.Buffer inSize+1]
print(b.length())
var c = api.Buffer(inSize+1)
assert 0 === c.length()
c.append(b)
//print(inSize,c.capacity(),c.length(),b.capacity(),b.length())
assert c.length() === b.length()
assert c === b // special case for buffer comparison compares underlying memory
if(0){
assert catch{
c.append('hi')
assert c === b // will fail
}
}
//[c.append b] // bug (in th1ish): this is appending very wrongly
//[c.append [b.toString]] // but this is very inefficient
// Make some changes to it...
const corruptOffset = 250/**
try to keep this in the middle of a UTF8 char, just to break
things. */
[c.fill 42 corruptOffset 20]
assert 42 === [c.byteAt corruptOffset+3]
const bLen = [b.length]
[c.fill 42 bLen/2 30]
assert 42 === [c.byteAt bLen/2]
const cStr = [c.toString]
//[print "<<<<<"[cStr]">>>>>"]
/**
If corruptOffset is set as commented above then
then 'c', cStr, and the applied delta will contain an
invalid (or unintended) UTF8 char at byte offset
(corruptOffset-1).
*/
// Create a delta...
const d = [Fossil.delta.create b c]
const dStr = [d.toString]
//[print 'Delta: ' dStr]
[print "Delta's applied length=" [Fossil.delta.appliedLength d]]
// Apply the delta to the original...
const a = [Fossil.delta.apply b d], aStr = [a.toString]
//[print "Applied delta" dStr]
// And assure that the original meets expectations...
assert aStr === cStr // Uses memcmp() instead of UTF8-validating compare
[print "Delta playback/comparison worked."]
// But note that applying a delta will fail if fossil
// detects any foul play...
assert Fossil.rc.CHECKSUM_MISMATCH === catch{
// Corrupt the delta and try to apply it:
[d.byteAt 20 3]
[Fossil.delta.apply b d]
}.code
print("Correctly failed to apply corrupted delta.")
0 && [print aStr] // remember: invalid UTF8
}