ManifestWriter.java

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// SPDX-License-Identifier: Apache-2.0
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// Copyright 2026 Egothor
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// Copyright 2026 Accenture
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package org.egothor.methodatlas.evidence;
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import java.io.BufferedWriter;
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import java.io.IOException;
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import java.io.InputStream;
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import java.nio.charset.StandardCharsets;
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import java.nio.file.Files;
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import java.nio.file.Path;
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import java.security.MessageDigest;
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import java.security.NoSuchAlgorithmException;
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import java.util.ArrayList;
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import java.util.Collections;
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import java.util.HexFormat;
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import java.util.List;
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import java.util.stream.Stream;
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/**
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 * Builds the {@code manifest.sha256} file that anchors an evidence pack.
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 *
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 * <p>
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 * The manifest enumerates every file in the pack directory other than
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 * itself and any {@code .signed} sibling, listing one entry per line in the
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 * format {@code <hex-digest>  <filename>}. Files are sorted lexicographically
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 * by filename so the manifest is byte-stable between runs that produce the
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 * same artefacts.
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 * </p>
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 *
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 * <p>
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 * Package-private because nothing outside the evidence module needs to call
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 * this writer.
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 * </p>
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 */
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final class ManifestWriter {
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    /** Java standard digest algorithm name for SHA-256. */
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    private static final String DIGEST_ALGORITHM = "SHA-256";
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    /** Buffer size used when streaming files through the digest. */
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    private static final int BUFFER_SIZE = 8192;
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    /** Filename suffix marking a signed-envelope sibling that must be excluded. */
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    private static final String SIGNED_SUFFIX = ".signed";
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    /** Two-space separator required by the shasum/coreutils manifest format. */
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    private static final String SEPARATOR = "  ";
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    private ManifestWriter() {
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        // Utility class — instantiation makes no sense.
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    }
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    /**
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     * Writes a SHA-256 manifest of every regular file in {@code dir}, except
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     * {@code manifestFile} itself and any file whose name ends with
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     * {@code .signed}.
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     *
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     * @param dir          directory to enumerate; must exist
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     * @param manifestFile output path; overwritten if it already exists
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     * @throws IOException if directory listing, digest computation, or
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     *                     writing fails
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     */
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    /* default */ static void write(Path dir, Path manifestFile) throws IOException {
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        List<Path> files = collectFiles(dir, manifestFile);
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        try (BufferedWriter writer = Files.newBufferedWriter(manifestFile, StandardCharsets.UTF_8)) {
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            for (Path file : files) {
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                String digest = sha256Hex(file);
69 1 1. write : removed call to java/io/BufferedWriter::write → KILLED
 
                writer.write(digest);
70 1 1. write : removed call to java/io/BufferedWriter::write → KILLED
 
                writer.write(SEPARATOR);
71 1 1. write : removed call to java/io/BufferedWriter::write → KILLED
 
                writer.write(filenameOf(file));
72 1 1. write : removed call to java/io/BufferedWriter::write → KILLED
 
                writer.write('\n');
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            }
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        }
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    }
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    /**
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     * Returns the filename portion of {@code p} as a non-null string. Used
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     * defensively because {@link Path#getFileName()} can theoretically
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     * return {@code null} (root paths); inside {@link Files#list(Path)}
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     * results that case is unreachable, but SpotBugs flags the chained
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     * {@code toString()} on a possibly-null return.
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     *
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     * @param p path to inspect
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     * @return filename as string; never {@code null}
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     */
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    private static String filenameOf(Path p) {
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        Path name = p.getFileName();
89 3 1. filenameOf : removed conditional - replaced equality check with false → SURVIVED
2. filenameOf : replaced return value with "" for org/egothor/methodatlas/evidence/ManifestWriter::filenameOf → KILLED
3. filenameOf : removed conditional - replaced equality check with true → KILLED
 
        return name == null ? "" : name.toString();
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    }
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    /**
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     * Lists candidate files in lexicographic order.
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     *
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     * @param dir          directory to enumerate
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     * @param manifestFile manifest path to exclude
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     * @return sorted list of files eligible for inclusion
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     * @throws IOException if the directory cannot be listed
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     */
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    private static List<Path> collectFiles(Path dir, Path manifestFile) throws IOException {
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        List<Path> files = new ArrayList<>();
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        try (Stream<Path> stream = Files.list(dir)) {
103 2 1. lambda$collectFiles$0 : replaced boolean return with true for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$0 → SURVIVED
2. lambda$collectFiles$0 : replaced boolean return with false for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$0 → KILLED
 
            stream.filter(Files::isRegularFile)
104 3 1. lambda$collectFiles$1 : removed conditional - replaced equality check with false → KILLED
2. lambda$collectFiles$1 : replaced boolean return with true for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$1 → KILLED
3. lambda$collectFiles$1 : removed conditional - replaced equality check with true → KILLED
 
                    .filter(p -> !p.equals(manifestFile))
105 3 1. lambda$collectFiles$2 : removed conditional - replaced equality check with true → KILLED
2. lambda$collectFiles$2 : replaced boolean return with true for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$2 → KILLED
3. lambda$collectFiles$2 : removed conditional - replaced equality check with false → KILLED
 
                    .filter(p -> !filenameOf(p).endsWith(SIGNED_SUFFIX))
106 1 1. collectFiles : removed call to java/util/stream/Stream::forEach → KILLED
 
                    .forEach(files::add);
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        }
108 2 1. collectFiles : removed call to java/util/Collections::sort → SURVIVED
2. lambda$collectFiles$3 : replaced int return with 0 for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$3 → SURVIVED
 
        Collections.sort(files, (a, b) -> filenameOf(a).compareTo(filenameOf(b)));
109 1 1. collectFiles : replaced return value with Collections.emptyList for org/egothor/methodatlas/evidence/ManifestWriter::collectFiles → KILLED
 
        return files;
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    }
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    /**
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     * Computes a lowercase-hex SHA-256 digest of the supplied file.
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     *
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     * @param file path to digest
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     * @return 64-character lowercase hex string
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     * @throws IOException if reading fails or SHA-256 is unavailable
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     */
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    private static String sha256Hex(Path file) throws IOException {
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        MessageDigest digest = newDigest();
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        byte[] buffer = new byte[BUFFER_SIZE];
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        try (InputStream in = Files.newInputStream(file)) {
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            int read;
124 3 1. sha256Hex : changed conditional boundary → SURVIVED
2. sha256Hex : removed conditional - replaced comparison check with false → KILLED
3. sha256Hex : removed conditional - replaced comparison check with true → KILLED
 
            while ((read = in.read(buffer)) >= 0) {
125 1 1. sha256Hex : removed call to java/security/MessageDigest::update → KILLED
 
                digest.update(buffer, 0, read);
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            }
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        }
128 1 1. sha256Hex : replaced return value with "" for org/egothor/methodatlas/evidence/ManifestWriter::sha256Hex → KILLED
 
        return HexFormat.of().formatHex(digest.digest());
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    }
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    /**
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     * Creates a fresh SHA-256 digest, wrapping the checked exception into an
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     * {@link IOException} so callers do not need a separate catch clause.
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     *
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     * @return new {@link MessageDigest} instance
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     * @throws IOException when SHA-256 is unexpectedly unavailable (never on a
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     *                     standard JDK)
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     */
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    private static MessageDigest newDigest() throws IOException {
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        try {
141 1 1. newDigest : replaced return value with null for org/egothor/methodatlas/evidence/ManifestWriter::newDigest → KILLED
 
            return MessageDigest.getInstance(DIGEST_ALGORITHM);
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        } catch (NoSuchAlgorithmException e) {
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            throw new IOException("SHA-256 not available", e);
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        }
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    }
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}

Mutations

69

1.1
Location : write
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeListsFilesLexicographicallyAndComputesSha256(java.nio.file.Path)] removed call to java/io/BufferedWriter::write → KILLED

70

1.1
Location : write
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed call to java/io/BufferedWriter::write → KILLED

71

1.1
Location : write
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed call to java/io/BufferedWriter::write → KILLED

72

1.1
Location : write
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeListsFilesLexicographicallyAndComputesSha256(java.nio.file.Path)] removed call to java/io/BufferedWriter::write → KILLED

89

1.1
Location : filenameOf
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] replaced return value with "" for org/egothor/methodatlas/evidence/ManifestWriter::filenameOf → KILLED

2.2
Location : filenameOf
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed conditional - replaced equality check with true → KILLED

3.3
Location : filenameOf
Killed by : none removed conditional - replaced equality check with false → SURVIVED Covering tests

103

1.1
Location : lambda$collectFiles$0
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] replaced boolean return with false for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$0 → KILLED

2.2
Location : lambda$collectFiles$0
Killed by : none replaced boolean return with true for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$0 → SURVIVED Covering tests

104

1.1
Location : lambda$collectFiles$1
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed conditional - replaced equality check with false → KILLED

2.2
Location : lambda$collectFiles$1
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] replaced boolean return with true for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$1 → KILLED

3.3
Location : lambda$collectFiles$1
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed conditional - replaced equality check with true → KILLED

105

1.1
Location : lambda$collectFiles$2
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed conditional - replaced equality check with true → KILLED

2.2
Location : lambda$collectFiles$2
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] replaced boolean return with true for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$2 → KILLED

3.3
Location : lambda$collectFiles$2
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed conditional - replaced equality check with false → KILLED

106

1.1
Location : collectFiles
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed call to java/util/stream/Stream::forEach → KILLED

108

1.1
Location : collectFiles
Killed by : none removed call to java/util/Collections::sort → SURVIVED Covering tests

2.2
Location : lambda$collectFiles$3
Killed by : none replaced int return with 0 for org/egothor/methodatlas/evidence/ManifestWriter::lambda$collectFiles$3 → SURVIVED Covering tests

109

1.1
Location : collectFiles
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] replaced return value with Collections.emptyList for org/egothor/methodatlas/evidence/ManifestWriter::collectFiles → KILLED

124

1.1
Location : sha256Hex
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeListsFilesLexicographicallyAndComputesSha256(java.nio.file.Path)] removed conditional - replaced comparison check with false → KILLED

2.2
Location : sha256Hex
Killed by : none changed conditional boundary → SURVIVED Covering tests

3.3
Location : sha256Hex
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] removed conditional - replaced comparison check with true → KILLED

125

1.1
Location : sha256Hex
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeListsFilesLexicographicallyAndComputesSha256(java.nio.file.Path)] removed call to java/security/MessageDigest::update → KILLED

128

1.1
Location : sha256Hex
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeListsFilesLexicographicallyAndComputesSha256(java.nio.file.Path)] replaced return value with "" for org/egothor/methodatlas/evidence/ManifestWriter::sha256Hex → KILLED

141

1.1
Location : newDigest
Killed by : org.egothor.methodatlas.evidence.ManifestWriterTest.[engine:junit-jupiter]/[class:org.egothor.methodatlas.evidence.ManifestWriterTest]/[method:writeExcludesManifestAndSignedSiblings(java.nio.file.Path)] replaced return value with null for org/egothor/methodatlas/evidence/ManifestWriter::newDigest → KILLED

Active mutators

Tests examined


Report generated by PIT 1.22.1