Add 3 blank lines between lock entries to minimize merge conflicts

README.md

@@ -36,7 +36,7 @@ Direct dependencies are specified in a top level `versions.props` file and then
 4. Run **`./gradlew --write-locks`** and see your versions.lock file be automatically created. This file should be checked into your repo:
 
     ```bash
-    # Run ./gradlew --write-locks to regenerate this file
+    # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
     com.squareup.okhttp3:okhttp:3.12.0 (1 constraints: 38053b3b)
     com.squareup.okio:okio:1.15.0 (1 constraints: 810cbb09)
     ```

changelog/@unreleased/pr-1001.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Add 3 blank lines between lock entries to minimize merge conflicts
+  links:
+  - https://github.com/palantir/gradle-consistent-versions/pull/1001

src/main/java/com/palantir/gradle/versions/ConflictSafeLockFile.java

@@ -35,7 +35,8 @@
 import org.gradle.api.GradleException;
 
 final class ConflictSafeLockFile {
-    private static final String HEADER_COMMENT = "# Run ./gradlew --write-locks to regenerate this file";
+    private static final String HEADER_COMMENT =
+            "# Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.";
     private static final Pattern LINE_PATTERN =
             Pattern.compile("(?<group>[^(:]+):(?<artifact>[^(:]+):(?<version>[^(:\\s]+)"
                     + "\\s+\\((?<num>\\d+) constraints: (?<hash>\\w+)\\)");
@@ -49,16 +50,14 @@ final class ConflictSafeLockFile {
 
     /** Reads and returns the {@link LockState}. */
     public LockState readLocks() {
-        try (Stream<String> linesStream = Files.lines(lockfile)) {
+        try (Stream<String> linesStream = Files.lines(lockfile).filter(line -> !line.isBlank())) {
             List<String> lines =
                     linesStream.filter(line -> !line.trim().startsWith("#")).collect(Collectors.toList());
             int testDependenciesPosition = lines.indexOf(TEST_DEPENDENCIES_MARKER);
             Stream<String> productionDeps;
             Stream<String> testDeps;
-            if (testDependenciesPosition >= 0) {
-                productionDeps = lines
-                        .subList(0, testDependenciesPosition - 1) // skip blank line before marker
-                        .stream();
+            if (testDependenciesPosition >= 0 && testDependenciesPosition + 1 < lines.size()) {
+                productionDeps = lines.subList(0, testDependenciesPosition).stream();
                 testDeps = lines.subList(testDependenciesPosition + 1, lines.size()).stream();
             } else {
                 productionDeps = lines.stream().filter(line -> !line.trim().startsWith("#"));
@@ -74,6 +73,7 @@ public LockState readLocks() {
 
     public Stream<Line> parseLines(Stream<String> stringStream) {
         return stringStream
+                .filter(line -> !line.isBlank())
                 .map(line -> {
                     Matcher matcher = LINE_PATTERN.matcher(line);
                     Preconditions.checkState(

src/main/java/com/palantir/gradle/versions/VerifyLocksTask.java

@@ -107,8 +107,8 @@ private static String formatDependencyDifferences(Map<MyModuleIdentifier, ValueD
                         "" // to align strings
                                 + "-%s\n"
                                 + "+%s",
-                        diff.getValue().leftValue().stringRepresentation(),
-                        diff.getValue().rightValue().stringRepresentation()))
+                        diff.getValue().leftValue().lockLine(),
+                        diff.getValue().rightValue().lockLine()))
                 .collect(Collectors.joining("\n"));
     }
 }

src/main/java/com/palantir/gradle/versions/lockstate/Line.java

@@ -46,7 +46,12 @@ default MyModuleIdentifier identifier() {
 
     @Lazy
     default String stringRepresentation() {
-        return String.format(
-                "%s:%s:%s (%s constraints: %s)", group(), name(), version(), numDependents(), dependentsHash());
+        // Three blank lines to avoid conflicts with automated upgrades
+        return "\n\n\n" + lockLine();
+    }
+
+    default String lockLine() {
+        return group() + ':' + name() + ':' + version() + " (" + numDependents() + " constraints: " + dependentsHash()
+                + ')';
     }
 }

src/main/java/com/palantir/gradle/versions/lockstate/LockStates.java

@@ -66,7 +66,7 @@ private static Line componentWithDependentsToLine(ModuleVersionIdentifier compon
 
         Line line = ImmutableLine.of(
                 component.getGroup(), component.getName(), component.getVersion(), all.size(), hash.toString());
-        log.info("{}: {}", line.stringRepresentation(), all);
+        log.info("{}: {}", line.lockLine(), all);
         return line;
     }
 

src/test/groovy/com/palantir/gradle/versions/ConsistentVersionsPluginIntegrationSpec.groovy

@@ -246,8 +246,14 @@ class ConsistentVersionsPluginIntegrationSpec extends IntegrationSpec {
 
         then:
         def expectedLock = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
+
+
+
             test-alignment:module-that-should-be-aligned-up:1.1 (1 constraints: a5041a2c)
+
+
+
             test-alignment:module-with-higher-version:1.1 (1 constraints: a6041b2c)
         """.stripIndent()
         file('versions.lock').text == expectedLock
@@ -276,7 +282,10 @@ class ConsistentVersionsPluginIntegrationSpec extends IntegrationSpec {
 
         then:
         def expectedLock = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
+
+
+
             org.slf4j:slf4j-api:1.7.25 (1 constraints: 4105483b)
         """.stripIndent()
         file('versions.lock').text == expectedLock
@@ -334,9 +343,18 @@ class ConsistentVersionsPluginIntegrationSpec extends IntegrationSpec {
         runTasks('--write-locks')
 
         file('versions.lock').text == """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
+
+
+
             org.slf4j:slf4j-api:1.7.25 (1 constraints: 4105483b)
+
+
+
             org1:platform:1.0 (1 constraints: a5041a2c)
+
+
+
             org2:platform:1.0 (1 constraints: a5041a2c)
         """.stripIndent()
 

src/test/groovy/com/palantir/gradle/versions/VersionsLockPluginIntegrationSpec.groovy

@@ -604,7 +604,10 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
 
         then:
         file('versions.lock').readLines() == [
-                '# Run ./gradlew --write-locks to regenerate this file',
+                '# Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.',
+                '',
+                '',
+                '',
                 'org:platform:1.0 (1 constraints: a5041a2c)',
         ]
 
@@ -687,8 +690,14 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
 
         then: 'slf4j-api still appears in the lock file'
         file('versions.lock').readLines() == [
-                '# Run ./gradlew --write-locks to regenerate this file',
+                '# Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.',
+                '',
+                '',
+                '',
                 'ch.qos.logback:logback-classic:1.2.3 (1 constraints: 0805f935)',
+                '',
+                '',
+                '',
                 'org.slf4j:slf4j-api:1.7.25 (1 constraints: 400d4d2a)',
         ]
 
@@ -774,11 +783,20 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
         expect:
         runTasks('--write-locks')
         def expected = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
+
+
+
             ch.qos.logback:logback-classic:1.2.3 (1 constraints: 0805f935)
+
+
+
             org.slf4j:slf4j-api:1.7.25 (2 constraints: 7917e690)
-             
+
             [Test dependencies]
+
+
+
             org:test-dep-that-logs:1.0 (1 constraints: a5041a2c)
         """.stripIndent()
         file('versions.lock').text == expected
@@ -806,12 +824,24 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
         expect:
         runTasks('--write-locks')
         def expected = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
+
+
+
             ch.qos.logback:logback-classic:1.2.3 (1 constraints: 0805f935)
+
+
+
             org.slf4j:slf4j-api:1.7.25 (2 constraints: 7917e690)
-             
+
             [Test dependencies]
+
+
+
             junit:junit:4.10 (1 constraints: d904fd30)
+
+
+
             org:test-dep-that-logs:1.0 (1 constraints: a5041a2c)
         """.stripIndent()
         file('versions.lock').text == expected
@@ -836,9 +866,12 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
         expect:
         runTasks('--write-locks')
         def expected = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
 
             [Test dependencies]
+
+
+
             junit:junit:4.10 (1 constraints: d904fd30)
         """.stripIndent()
         file('versions.lock').text == expected
@@ -866,10 +899,16 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
         expect:
         runTasks('--write-locks')
         def expected = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
 
             [Test dependencies]
+
+
+
             ch.qos.logback:logback-classic:1.2.3 (1 constraints: 0805f935)
+
+
+
             org.slf4j:slf4j-api:1.7.25 (1 constraints: 400d4d2a)
         """.stripIndent()
         file('versions.lock').text == expected
@@ -1098,8 +1137,14 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
         expect:
         runTasks("--write-locks")
         file('versions.lock').text == """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
+
+
+
             ch.qos.logback:logback-classic:1.2.3 (1 constraints: 0805f935)
+
+
+
             org.slf4j:slf4j-api:1.7.25 (2 constraints: 8012a437)
         """.stripIndent()
 
@@ -1118,7 +1163,7 @@ class VersionsLockPluginIntegrationSpec extends IntegrationSpec {
         """.stripIndent()
 
         def lockFileContent = """\
-            # Run ./gradlew --write-locks to regenerate this file
+            # Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
         """.stripIndent()
 
         file('versions.lock').text = lockFileContent

src/test/resources/sample-versions.lock

@@ -1,4 +1,4 @@
-# Run ./gradlew --write-locks to regenerate this file
+# Run ./gradlew --write-locks to regenerate this file. Blank lines are to minimize merge conflicts.
 aopalliance:aopalliance:1.0 (1 constraints: 170a83ac)
 ch.qos.logback:logback-access:1.2.3 (3 constraints: 4f354f15)
 ch.qos.logback:logback-classic:1.2.3 (5 constraints: 9351d6aa)