Add configurable line length and configuration-aware caching

.github/workflows/ci.yml

@@ -57,19 +57,19 @@ jobs:
     - name: Build and test (sbt 1.x)
       if: ${{ matrix.jobtype == 1 }}
       shell: bash
-      run: sbt -v '++ 2.12.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted sbt-java-formatter/*' 'scripted java-runtime/compatible-11'
+      run: sbt -v '++ 2.12.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted sbt-java-formatter/*' 'scripted java-runtime/compatible-11' 'scripted java-runtime/cache-runtime-on-java-11'
     - name: Build and test (sbt 2.x)
       if: ${{ matrix.jobtype == 2 }}
       shell: bash
       run: sbt -v '++ 3.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted sbt-java-formatter/*' 'scripted java-runtime/compatible-17' 'scripted java-runtime/incompatible-21-on-java-17'
     - name: Build and test (sbt 2.x, Java 21)
       if: ${{ matrix.jobtype == 3 }}
       shell: bash
-      run: sbt -v '++ 3.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted sbt-java-formatter/*' 'scripted java-runtime/compatible-21' 'scripted java-runtime/reorder-modifiers'
+      run: sbt -v '++ 3.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted sbt-java-formatter/*' 'scripted java-runtime/compatible-21' 'scripted java-runtime/reorder-modifiers' 'scripted java-runtime/max-line-length'
     - name: Build and test (sbt 2.x, Java 25)
       if: ${{ matrix.jobtype == 4 }}
       shell: bash
-      run: sbt -v '++ 3.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted java-runtime/compatible-21' 'scripted java-runtime/reorder-modifiers'
+      run: sbt -v '++ 3.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted java-runtime/compatible-21' 'scripted java-runtime/reorder-modifiers' 'scripted java-runtime/max-line-length'
     - name: Build and test (sbt 1.x, Java 11 with formatter on Java 25)
       if: ${{ matrix.jobtype == 5 }}
       shell: bash
@@ -78,4 +78,4 @@ jobs:
         SBT_JAVAFMT_JAVA_HOME: ${{ env.JAVA_HOME_25_X64 }}
       run: |
         export PATH="${JAVA_HOME}/bin:$PATH"
-        sbt -v '++ 2.12.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted java-runtime/compatible-21' 'scripted java-runtime/reorder-modifiers'
+        sbt -v '++ 2.12.x' clean scalafmtSbtCheck scalafmtCheckAll test 'scripted java-runtime/compatible-21' 'scripted java-runtime/reorder-modifiers' 'scripted java-runtime/max-line-length'

README.md

@@ -34,6 +34,7 @@ For available versions see [releases](https://github.com/sbt/sbt-java-formatter/
 
 * The `javafmtOnCompile` setting controls whether the formatter kicks in on compile (`false` by default).
 * The `javafmtStyle` setting defines the formatting style: Google Java Style (by default) or AOSP style.
+* The `javafmtMaxLineLength` setting controls the maximum line length (`100` by default). Custom values require `javafmtFormatterCompatibleJavaVersion := 21`.
 * The `javafmtSortImports` setting controls whether imports are sorted (`true` by default).
 * The `javafmtRemoveUnusedImports` setting controls whether unused imports are removed (`true` by default).
 * The `javafmtReflowLongStrings` setting controls whether long string literals are reflowed (`true` by default).
@@ -86,7 +87,7 @@ SBT_JAVAFMT_JAVA_HOME=/path/to/jdk-17 sbt javafmt
 > [!NOTE]
 > Many projects use Java 17 as their baseline today. If that is true for your build, `ThisBuild / javafmtFormatterCompatibleJavaVersion := 17` is often the simplest setup.
 >
-> The main Java language support changes in `google-java-format` [after `v1.28.0`](https://github.com/google/google-java-format/compare/v1.28.0...v1.36.1) are:
+> The main Java language support changes in `google-java-format` [after `v1.28.0`](https://github.com/google/google-java-format/compare/v1.28.0...v1.37.0) are:
 >
 > - [Initial support for import module in google-java-format](https://github.com/google/google-java-format/commit/6afe380707ec16884ec2761763ccec998de403d1)
 > - [Support Instance Main Methods in google-java-format](https://github.com/google/google-java-format/commit/737b0032b3a18eb6e458271ea440098c166f6c2d)
@@ -119,13 +120,35 @@ ThisBuild / javafmtFormatJavadoc := true
 ThisBuild / javafmtReorderModifiers := true
 ```
 
-Set any of them to `false` to pass the corresponding `--skip-...` flag to `google-java-format`.
+Set the Boolean formatter options to `false` to pass the corresponding `--skip-...` flag to `google-java-format`.
+
+Use `javafmtStyle` to select Google or AOSP style, which is equivalent to the CLI's `--style=google` / `--style=aosp` options (`--google-style` / `--aosp`):
+
+```scala
+import com.google.googlejavaformat.java.JavaFormatterOptions
+
+ThisBuild / javafmtStyle := JavaFormatterOptions.Style.GOOGLE
+// Or: ThisBuild / javafmtStyle := JavaFormatterOptions.Style.AOSP
+```
+
+Use `javafmtMaxLineLength` to customize the line width used for code, comments, and long string reflow:
+
+```scala
+ThisBuild / javafmtFormatterCompatibleJavaVersion := 21
+ThisBuild / javafmtMaxLineLength := 120
+```
+
+The value must be positive. The default of `100` works with all formatter runtime lines; custom values require the Java 21 line because the Java 11 and Java 17 lines do not support `--max-line-length`.
+
+Only `javafmtStyle`, `javafmtSortImports`, and `javafmtRemoveUnusedImports` affect the output of the `javafmtFixImports...` tasks. Full-formatting options (line length, Javadoc formatting, modifier reordering, and long string reflow) are ignored and not validated for import-only tasks, even on older formatter runtime lines.
+
+Formatting and check caches are invalidated when effective formatter options or the formatter runtime change, even if source files have not changed. Import-only tasks use a separate cache from full-formatting tasks; changes to full-formatting options do not invalidate their cache.
 
 `javafmtFormatterCompatibleJavaVersion` maps to these formatter versions:
 
 - `11` -> `google-java-format 1.24.0`
 - `17` -> `google-java-format 1.28.0`
-- `21` -> `google-java-format 1.36.1` (default)
+- `21` -> `google-java-format 1.37.0` (default)
 
 If the selected formatter runtime is newer than the Java used to launch the formatter JVM, either:
 

plugin/src/main/scala/com/github/sbt/JavaFormatterPlugin.scala

@@ -72,6 +72,9 @@ object JavaFormatterPlugin extends AutoPlugin {
         "Selects the google-java-format runtime line by compatible Java version. Supported values: 11, 17, 21.")
     val javafmtStyle =
       settingKey[JavaFormatterOptions.Style]("Define formatting style, Google Java Style (default) or AOSP")
+    val javafmtMaxLineLength =
+      settingKey[Int](
+        s"Maximum line length used by google-java-format. Defaults to ${JavaFormatter.DefaultMaxLineLength}; custom values require the Java 21 formatter runtime line.")
     val javafmtJavaMaxHeap =
       settingKey[Option[String]]("Maximum heap size passed to the forked google-java-format JVM, e.g. Some(\"256m\").")
     val javafmtSortImports =
@@ -119,6 +122,7 @@ object JavaFormatterPlugin extends AutoPlugin {
       javafmtOnCompile := false,
       javafmtFormatterCompatibleJavaVersion := 21,
       javafmtStyle := JavaFormatterOptions.Style.GOOGLE,
+      javafmtMaxLineLength := JavaFormatter.DefaultMaxLineLength,
       javafmtJavaMaxHeap := Some("256m"),
       javafmtSortImports := true,
       javafmtRemoveUnusedImports := true,
@@ -143,8 +147,9 @@ object JavaFormatterPlugin extends AutoPlugin {
         val iF = (javafmt / includeFilter).value
         val eF = (javafmt / excludeFilter).value
         val cache = streamz.cacheStoreFactory
+        val maxLineLength = javafmtMaxLineLength.value
         val options =
-          validateOptions(javafmtOptions.value, javafmtFormatterCompatibleJavaVersion.value)
+          validateOptions(javafmtOptions.value, javafmtFormatterCompatibleJavaVersion.value, maxLineLength)
         val formatterClasspath = javafmtFormatterClasspath.value.toVector
         val javaMaxHeap = javafmtJavaMaxHeap.value
         val sortImports = javafmtSortImports.value
@@ -163,7 +168,8 @@ object JavaFormatterPlugin extends AutoPlugin {
           javaMaxHeap,
           sortImports,
           removeUnusedImports,
-          reflowLongStrings)
+          reflowLongStrings,
+          maxLineLength)
       },
       javafmtCheck := {
         val streamz = streams.value
@@ -174,8 +180,9 @@ object JavaFormatterPlugin extends AutoPlugin {
         val iF = (javafmt / includeFilter).value
         val eF = (javafmt / excludeFilter).value
         val cache = (javafmt / streams).value.cacheStoreFactory
+        val maxLineLength = javafmtMaxLineLength.value
         val options =
-          validateOptions(javafmtOptions.value, javafmtFormatterCompatibleJavaVersion.value)
+          validateOptions(javafmtOptions.value, javafmtFormatterCompatibleJavaVersion.value, maxLineLength)
         val formatterClasspath = javafmtFormatterClasspath.value.toVector
         val javaMaxHeap = javafmtJavaMaxHeap.value
         val sortImports = javafmtSortImports.value
@@ -195,7 +202,8 @@ object JavaFormatterPlugin extends AutoPlugin {
           javaMaxHeap,
           sortImports,
           removeUnusedImports,
-          reflowLongStrings)
+          reflowLongStrings,
+          maxLineLength)
       },
       javafmtFixImports := {
         val streamz = streams.value
@@ -204,14 +212,12 @@ object JavaFormatterPlugin extends AutoPlugin {
         val sD = (javafmt / sourceDirectories).value.toList
         val iF = (javafmt / includeFilter).value
         val eF = (javafmt / excludeFilter).value
-        val cache = streamz.cacheStoreFactory
-        val options =
-          validateOptions(javafmtOptions.value, javafmtFormatterCompatibleJavaVersion.value)
+        val cache = (javafmt / streams).value.cacheStoreFactory
+        val options = javafmtOptions.value
         val formatterClasspath = javafmtFormatterClasspath.value.toVector
         val javaMaxHeap = javafmtJavaMaxHeap.value
         val sortImports = javafmtSortImports.value
         val removeUnusedImports = javafmtRemoveUnusedImports.value
-        val reflowLongStrings = javafmtReflowLongStrings.value
         JavaFormatter.fixImports(
           projectId,
           invocationId,
@@ -224,8 +230,7 @@ object JavaFormatterPlugin extends AutoPlugin {
           formatterClasspath,
           javaMaxHeap,
           sortImports,
-          removeUnusedImports,
-          reflowLongStrings)
+          removeUnusedImports)
       },
       javafmtFixImportsCheck := {
         val streamz = streams.value
@@ -236,13 +241,11 @@ object JavaFormatterPlugin extends AutoPlugin {
         val iF = (javafmt / includeFilter).value
         val eF = (javafmt / excludeFilter).value
         val cache = (javafmt / streams).value.cacheStoreFactory
-        val options =
-          validateOptions(javafmtOptions.value, javafmtFormatterCompatibleJavaVersion.value)
+        val options = javafmtOptions.value
         val formatterClasspath = javafmtFormatterClasspath.value.toVector
         val javaMaxHeap = javafmtJavaMaxHeap.value
         val sortImports = javafmtSortImports.value
         val removeUnusedImports = javafmtRemoveUnusedImports.value
-        val reflowLongStrings = javafmtReflowLongStrings.value
         JavaFormatter.fixImportsCheck(
           projectId,
           invocationId,
@@ -256,8 +259,7 @@ object JavaFormatterPlugin extends AutoPlugin {
           formatterClasspath,
           javaMaxHeap,
           sortImports,
-          removeUnusedImports,
-          reflowLongStrings)
+          removeUnusedImports)
       },
       javafmtDoFormatOnCompile := Def.settingDyn {
         if (javafmtOnCompile.value) {
@@ -287,14 +289,27 @@ object JavaFormatterPlugin extends AutoPlugin {
     compatibleJavaVersion match {
       case 11    => "1.24.0"
       case 17    => "1.28.0"
-      case 21    => "1.36.1"
+      case 21    => "1.37.0"
       case other =>
         throw new MessageOnlyException(
           s"Unsupported javafmtFormatterCompatibleJavaVersion: $other. Expected one of: 11, 17, 21.")
     }
 
-  private def validateOptions(options: JavaFormatterOptions, compatibleJavaVersion: Int): JavaFormatterOptions = {
-    if (!options.reorderModifiers() && compatibleJavaVersion != 21) {
+  private def validateOptions(
+      options: JavaFormatterOptions,
+      compatibleJavaVersion: Int,
+      maxLineLength: Int): JavaFormatterOptions = {
+    if (maxLineLength <= 0) {
+      throw new MessageOnlyException(s"javafmtMaxLineLength must be positive, but was $maxLineLength.")
+    }
+    if (maxLineLength != JavaFormatter.DefaultMaxLineLength && compatibleJavaVersion < 21) {
+      throw new MessageOnlyException(
+        "A custom javafmtMaxLineLength requires " +
+        "ThisBuild / javafmtFormatterCompatibleJavaVersion := 21 " +
+        "because the Java 11 and Java 17 formatter runtime lines do not support " +
+        "--max-line-length.")
+    }
+    if (!options.reorderModifiers() && compatibleJavaVersion < 21) {
       throw new MessageOnlyException(
         "Disabling modifier reordering requires " +
         "ThisBuild / javafmtFormatterCompatibleJavaVersion := 21 " +