From 5b97b8e085269813f64a91314a77f7a4be8c1d56 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Tue, 21 May 2024 18:17:41 +0100
Subject: [PATCH 1/9] Move filename/stdin parsing logic to ParsedArgs

Checking whether we have a single filename '-' or multiple files, none
of which are '-' is parsing and should be part of the parsing step
---
 core/src/main/java/com/facebook/ktfmt/cli/Main.kt  | 14 ++------------
 .../main/java/com/facebook/ktfmt/cli/ParsedArgs.kt |  8 ++++++++
 .../test/java/com/facebook/ktfmt/cli/MainTest.kt   | 10 ----------
 .../java/com/facebook/ktfmt/cli/ParsedArgsTest.kt  |  6 ++++++
 4 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index fba648b3..a3a6104a 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -56,10 +56,6 @@ class Main(
       }
       val result = mutableListOf<File>()
       for (arg in args) {
-        if (arg == "-") {
-          error(
-              "Error: '-', which causes ktfmt to read from stdin, should not be mixed with file name")
-        }
         result.addAll(
             File(arg).walkTopDown().filter {
               it.isFile && (it.extension == "kt" || it.extension == "kts")
@@ -95,14 +91,8 @@ class Main(
       return 1
     }
 
-    val files: List<File>
-    try {
-      files = expandArgsToFileNames(parsedArgs.fileNames)
-    } catch (e: java.lang.IllegalStateException) {
-      err.println(e.message)
-      return 1
-    }
-
+    val files: List<File> = expandArgsToFileNames(parsedArgs.fileNames)
+    
     if (files.isEmpty()) {
       err.println("Error: no .kt files found")
       return 1
diff --git a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
index 6179f5db..d37b3bb6 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
@@ -76,6 +76,14 @@ data class ParsedArgs(
         }
       }
 
+      if (fileNames.contains("-") && fileNames.size > 1) {
+        val filesExceptStdin = fileNames - "-"
+        return ParseResult.Error(
+          "Cannot read from stdin and files in same run. Found stdin specifier '-'" +
+              " and files ${filesExceptStdin.joinToString(", ")} "
+        )
+      }
+
       return ParseResult.Ok(
           ParsedArgs(
               fileNames,
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
index 925ad271..5c046db8 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
@@ -104,16 +104,6 @@ class MainTest {
         .containsExactly(foo1, bar1, foo2, bar2)
   }
 
-  @Test
-  fun `expandArgsToFileNames - a dash is an error`() {
-    try {
-      Main.expandArgsToFileNames(listOf(root.resolve("foo.bar").toString(), File("-").toString()))
-      fail("expected exception, but nothing was thrown")
-    } catch (e: IllegalStateException) {
-      assertThat(e.message).contains("Error")
-    }
-  }
-
   @Test
   fun `Using '-' as the filename formats an InputStream`() {
     val code = "fun    f1 (  ) :    Int =    0"
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
index 72f9bec2..2e019014 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
@@ -121,6 +121,12 @@ class ParsedArgsTest {
     assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
   }
 
+  @Test
+  fun `parseOptions rejects '-' and files at the same time`() {
+    val parseResult = ParsedArgs.parseOptions(arrayOf("-", "File.kt"))
+    assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
+  }
+
   @Test
   fun `processArgs use the @file option with non existing file`() {
     val e =

From b2e59446fed0ef8f1f7f76d4aa4e3b5e1ce0c4b0 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Sun, 9 Jun 2024 16:31:56 +0100
Subject: [PATCH 2/9] Use --style=<style> in CLI

---
 .../main/java/com/facebook/ktfmt/cli/Main.kt  |  4 +--
 .../java/com/facebook/ktfmt/cli/ParsedArgs.kt | 24 +++++++++++++----
 .../java/com/facebook/ktfmt/cli/MainTest.kt   |  4 +--
 .../com/facebook/ktfmt/cli/ParsedArgsTest.kt  | 26 ++++++++++++++-----
 4 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index a3a6104a..36eeb784 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -74,7 +74,7 @@ class Main(
         }
     if (parsedArgs.fileNames.isEmpty()) {
       err.println(
-          "Usage: ktfmt [--dropbox-style | --google-style | --kotlinlang-style] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...")
+          "Usage: ktfmt [--style=dropbox|google|kotlinlang] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...")
       err.println("Or: ktfmt @file")
       return 1
     }
@@ -92,7 +92,7 @@ class Main(
     }
 
     val files: List<File> = expandArgsToFileNames(parsedArgs.fileNames)
-    
+
     if (files.isEmpty()) {
       err.println("Error: no .kt files found")
       return 1
diff --git a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
index d37b3bb6..1287d5a2 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
@@ -59,9 +59,21 @@ data class ParsedArgs(
 
       for (arg in args) {
         when {
-          arg == "--dropbox-style" -> formattingOptions = Formatter.DROPBOX_FORMAT
-          arg == "--google-style" -> formattingOptions = Formatter.GOOGLE_FORMAT
-          arg == "--kotlinlang-style" -> formattingOptions = Formatter.KOTLINLANG_FORMAT
+          arg.startsWith("--style=") -> {
+              val parsedStyle =
+                  parseKeyValueArg("--style", arg)
+                      ?: return ParseResult.Error(
+                          unexpectedArg(arg)
+                      )
+              formattingOptions = when (parsedStyle) {
+                  "dropbox" -> Formatter.DROPBOX_FORMAT
+                  "google" -> Formatter.GOOGLE_FORMAT
+                  "kotlinlang" -> Formatter.KOTLINLANG_FORMAT
+                  else -> return ParseResult.Error(
+                      "Unknown style '${parsedStyle}'. Style must be one of [dropbox, google, kotlinlang]."
+                  )
+              }
+          }
           arg == "--dry-run" || arg == "-n" -> dryRun = true
           arg == "--set-exit-if-changed" -> setExitIfChanged = true
           arg == "--do-not-remove-unused-imports" -> removeUnusedImports = false
@@ -70,8 +82,8 @@ data class ParsedArgs(
                   parseKeyValueArg("--stdin-name", arg)
                       ?: return ParseResult.Error(
                           "Found option '${arg}', expected '${"--stdin-name"}=<value>'")
-          arg.startsWith("--") -> return ParseResult.Error("Unexpected option: $arg")
-          arg.startsWith("@") -> return ParseResult.Error("Unexpected option: $arg")
+          arg.startsWith("--") -> return ParseResult.Error(unexpectedArg(arg))
+          arg.startsWith("@") -> return ParseResult.Error(unexpectedArg(arg))
           else -> fileNames.add(arg)
         }
       }
@@ -94,6 +106,8 @@ data class ParsedArgs(
           ))
     }
 
+    private fun unexpectedArg(arg: String) = "Unexpected option: $arg"
+
     private fun parseKeyValueArg(key: String, arg: String): String? {
       val parts = arg.split('=', limit = 2)
       return parts[1].takeIf { parts[0] == key || parts.size == 2 }
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
index 5c046db8..fb347dcc 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
@@ -244,7 +244,7 @@ class MainTest {
             emptyInput,
             PrintStream(out),
             PrintStream(err),
-            arrayOf("--dropbox-style", fooBar.toString()))
+            arrayOf("--style=dropbox", fooBar.toString()))
         .run()
 
     assertThat(fooBar.readText()).isEqualTo(code)
@@ -274,7 +274,7 @@ class MainTest {
             code.byteInputStream(),
             PrintStream(out),
             PrintStream(err),
-            arrayOf("--dropbox-style", "-"))
+            arrayOf("--style=dropbox", "-"))
         .run()
 
     assertThat(out.toString(UTF_8)).isEqualTo(formatted)
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
index 2e019014..7b810fbd 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
@@ -61,17 +61,29 @@ class ParsedArgsTest {
   }
 
   @Test
-  fun `parseOptions recognizes --dropbox-style`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--dropbox-style", "foo.kt")))
+  fun `parseOptions recognizes --style=dropbox`() {
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--style=dropbox", "foo.kt")))
     assertThat(parsed.formattingOptions).isEqualTo(Formatter.DROPBOX_FORMAT)
   }
 
   @Test
-  fun `parseOptions recognizes --google-style`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--google-style", "foo.kt")))
+  fun `parseOptions recognizes --style=google`() {
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--style=google", "foo.kt")))
     assertThat(parsed.formattingOptions).isEqualTo(Formatter.GOOGLE_FORMAT)
   }
 
+  @Test
+  fun `parseOptions recognizes --style=kotlinlang`() {
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--style=kotlinlang", "foo.kt")))
+    assertThat(parsed.formattingOptions).isEqualTo(Formatter.KOTLINLANG_FORMAT)
+  }
+
+  @Test
+  fun `parseOptions rejects unknown style`() {
+    val parseResult = ParsedArgs.parseOptions(arrayOf("--style=custom-style", "foo.kt"))
+    assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
+  }
+
   @Test
   fun `parseOptions recognizes --dry-run`() {
     val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--dry-run", "foo.kt")))
@@ -139,7 +151,7 @@ class ParsedArgsTest {
   @Test
   fun `processArgs use the @file option with file containing arguments`() {
     val file = root.resolve("existing-file")
-    file.writeText("--google-style\n--dry-run\n--set-exit-if-changed\nFile1.kt\nFile2.kt\n")
+    file.writeText("--style=google\n--dry-run\n--set-exit-if-changed\nFile1.kt\nFile2.kt\n")
 
     val result = ParsedArgs.processArgs(arrayOf("@" + file.absolutePath))
     assertThat(result).isInstanceOf(ParseResult.Ok::class.java)
@@ -156,7 +168,7 @@ class ParsedArgsTest {
   fun `parses multiple args successfully`() {
     val testResult =
         ParsedArgs.parseOptions(
-            arrayOf("--google-style", "--dry-run", "--set-exit-if-changed", "File.kt"),
+            arrayOf("--style=google", "--dry-run", "--set-exit-if-changed", "File.kt"),
         )
     assertThat(testResult)
         .isEqualTo(
@@ -171,7 +183,7 @@ class ParsedArgsTest {
   @Test
   fun `last style in args wins`() {
     val testResult =
-        ParsedArgs.parseOptions(arrayOf("--google-style", "--dropbox-style", "File.kt"))
+        ParsedArgs.parseOptions(arrayOf("--style=google", "--style=dropbox", "File.kt"))
     assertThat(testResult)
         .isEqualTo(
             parseResultOk(

From c5134ef48ceb7729e2d8969cd647b20875f07bac Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Sun, 9 Jun 2024 16:56:34 +0100
Subject: [PATCH 3/9] Move --stdin-name parsing logic to ParsedArgs

Similarly to 5b97b8e0, this logic is part of parsing the CLI args
---
 .../main/java/com/facebook/ktfmt/cli/Main.kt  |  5 +--
 .../java/com/facebook/ktfmt/cli/ParsedArgs.kt | 34 ++++++++++---------
 .../java/com/facebook/ktfmt/cli/MainTest.kt   | 21 ------------
 .../com/facebook/ktfmt/cli/ParsedArgsTest.kt  | 12 +++++--
 4 files changed, 28 insertions(+), 44 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index 36eeb784..d92afc45 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -86,10 +86,7 @@ class Main(
       } catch (e: Exception) {
         1
       }
-    } else if (parsedArgs.stdinName != null) {
-      err.println("Error: --stdin-name can only be used with stdin")
-      return 1
-    }
+    } 
 
     val files: List<File> = expandArgsToFileNames(parsedArgs.fileNames)
 
diff --git a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
index 1287d5a2..60cc4498 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
@@ -60,19 +60,17 @@ data class ParsedArgs(
       for (arg in args) {
         when {
           arg.startsWith("--style=") -> {
-              val parsedStyle =
-                  parseKeyValueArg("--style", arg)
-                      ?: return ParseResult.Error(
-                          unexpectedArg(arg)
-                      )
-              formattingOptions = when (parsedStyle) {
+            val parsedStyle =
+                parseKeyValueArg("--style", arg) ?: return ParseResult.Error(unexpectedArg(arg))
+            formattingOptions =
+                when (parsedStyle) {
                   "dropbox" -> Formatter.DROPBOX_FORMAT
                   "google" -> Formatter.GOOGLE_FORMAT
                   "kotlinlang" -> Formatter.KOTLINLANG_FORMAT
-                  else -> return ParseResult.Error(
-                      "Unknown style '${parsedStyle}'. Style must be one of [dropbox, google, kotlinlang]."
-                  )
-              }
+                  else ->
+                      return ParseResult.Error(
+                          "Unknown style '${parsedStyle}'. Style must be one of [dropbox, google, kotlinlang].")
+                }
           }
           arg == "--dry-run" || arg == "-n" -> dryRun = true
           arg == "--set-exit-if-changed" -> setExitIfChanged = true
@@ -88,12 +86,16 @@ data class ParsedArgs(
         }
       }
 
-      if (fileNames.contains("-") && fileNames.size > 1) {
-        val filesExceptStdin = fileNames - "-"
-        return ParseResult.Error(
-          "Cannot read from stdin and files in same run. Found stdin specifier '-'" +
-              " and files ${filesExceptStdin.joinToString(", ")} "
-        )
+      if (fileNames.contains("-")) {
+        // We're reading from stdin
+        if (fileNames.size > 1) {
+          val filesExceptStdin = fileNames - "-"
+          return ParseResult.Error(
+              "Cannot read from stdin and files in same run. Found stdin specifier '-'" +
+                  " and files ${filesExceptStdin.joinToString(", ")} ")
+        }
+      } else if (stdinName != null) {
+        return ParseResult.Error("--stdin-name can only be specified when reading from stdin")
       }
 
       return ParseResult.Ok(
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
index fb347dcc..d9432ddf 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
@@ -460,27 +460,6 @@ class MainTest {
     assertThat(exitCode).isEqualTo(1)
   }
 
-  @Test
-  fun `--stdin-name can only be used with stdin`() {
-    val code = """fun f () =    println( "hello, world" )"""
-    val file = root.resolve("foo.kt")
-    file.writeText(code, UTF_8)
-
-    val exitCode =
-        Main(
-                emptyInput,
-                PrintStream(out),
-                PrintStream(err),
-                arrayOf("--stdin-name=bar.kt", file.toString()))
-            .run()
-
-    assertThat(file.readText()).isEqualTo(code)
-    assertThat(out.toString(UTF_8)).isEmpty()
-    assertThat(err.toString(testCharset))
-        .isEqualTo("Error: --stdin-name can only be used with stdin\n")
-    assertThat(exitCode).isEqualTo(1)
-  }
-
   @Test
   fun `Always use UTF8 encoding (stdin, stdout)`() {
     val code = """fun f () =    println( "hello, world" )"""
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
index 7b810fbd..17dc6353 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
@@ -117,18 +117,18 @@ class ParsedArgsTest {
 
   @Test
   fun `parseOptions recognizes --stdin-name`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--stdin-name=my/foo.kt")))
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--stdin-name=my/foo.kt", "-")))
     assertThat(parsed.stdinName).isEqualTo("my/foo.kt")
   }
 
   @Test
   fun `parseOptions accepts --stdin-name with empty value`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--stdin-name=")))
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--stdin-name=", "-")))
     assertThat(parsed.stdinName).isEqualTo("")
   }
 
   @Test
-  fun `parseOptions --stdin-name without value`() {
+  fun `parseOptions rejects --stdin-name without value`() {
     val parseResult = ParsedArgs.parseOptions(arrayOf("--stdin-name"))
     assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
   }
@@ -139,6 +139,12 @@ class ParsedArgsTest {
     assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
   }
 
+  @Test
+  fun `parseOptions rejects --stdin-name when not reading from stdin`() {
+    val parseResult = ParsedArgs.parseOptions(arrayOf("--stdin-name=foo","file1.kt"))
+    assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
+  }
+
   @Test
   fun `processArgs use the @file option with non existing file`() {
     val e =

From 84db31fb0987be36ff5bf1ba02e33d2a001bccac Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Sun, 9 Jun 2024 17:19:12 +0100
Subject: [PATCH 4/9] Use named constant for CLI error return code

---
 .../main/java/com/facebook/ktfmt/cli/Main.kt  | 24 +++++++++++--------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index d92afc45..6ea24327 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -32,6 +32,8 @@ import java.nio.charset.StandardCharsets.UTF_8
 import java.util.concurrent.atomic.AtomicInteger
 import kotlin.system.exitProcess
 
+private const val EXIT_CODE_FAILURE = 1
+
 class Main(
     private val input: InputStream,
     private val out: PrintStream,
@@ -70,39 +72,41 @@ class Main(
     val parsedArgs =
         when (processArgs) {
           is ParseResult.Ok -> processArgs.parsedValue
-          is ParseResult.Error -> exitFatal(processArgs.errorMessage, 1)
+          is ParseResult.Error -> {
+            err.println(processArgs.errorMessage)
+            return EXIT_CODE_FAILURE
+          }
         }
     if (parsedArgs.fileNames.isEmpty()) {
       err.println(
-          "Usage: ktfmt [--style=dropbox|google|kotlinlang] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...")
-      err.println("Or: ktfmt @file")
-      return 1
+          "Usage: ktfmt [--style=dropbox|google|kotlinlang] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...\nOr: ktfmt @file")
+      return EXIT_CODE_FAILURE
     }
 
     if (parsedArgs.fileNames.size == 1 && parsedArgs.fileNames[0] == "-") {
       return try {
         val alreadyFormatted = format(null, parsedArgs)
-        if (!alreadyFormatted && parsedArgs.setExitIfChanged) 1 else 0
+        if (!alreadyFormatted && parsedArgs.setExitIfChanged) EXIT_CODE_FAILURE else 0
       } catch (e: Exception) {
-        1
+        EXIT_CODE_FAILURE
       }
-    } 
+    }
 
     val files: List<File> = expandArgsToFileNames(parsedArgs.fileNames)
 
     if (files.isEmpty()) {
       err.println("Error: no .kt files found")
-      return 1
+      return EXIT_CODE_FAILURE
     }
 
     val retval = AtomicInteger(0)
     files.parallelStream().forEach {
       try {
         if (!format(it, parsedArgs) && parsedArgs.setExitIfChanged) {
-          retval.set(1)
+          retval.set(EXIT_CODE_FAILURE)
         }
       } catch (e: Exception) {
-        retval.set(1)
+        retval.set(EXIT_CODE_FAILURE)
       }
     }
     return retval.get()

From 37bb70316ab4b376fa5abf1a926f9eac65849920 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Mon, 10 Jun 2024 17:19:44 +0100
Subject: [PATCH 5/9] Use named constant CLI success return code

---
 .../src/main/java/com/facebook/ktfmt/cli/Main.kt | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index 6ea24327..ace92ca0 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -34,6 +34,8 @@ import kotlin.system.exitProcess
 
 private const val EXIT_CODE_FAILURE = 1
 
+private const val EXIT_CODE_SUCCESS = 0
+
 class Main(
     private val input: InputStream,
     private val out: PrintStream,
@@ -84,11 +86,16 @@ class Main(
     }
 
     if (parsedArgs.fileNames.size == 1 && parsedArgs.fileNames[0] == "-") {
-      return try {
+      // Format code read from stdin
+      try {
         val alreadyFormatted = format(null, parsedArgs)
-        if (!alreadyFormatted && parsedArgs.setExitIfChanged) EXIT_CODE_FAILURE else 0
+        return if (!alreadyFormatted && parsedArgs.setExitIfChanged)
+          EXIT_CODE_FAILURE
+        else
+          EXIT_CODE_SUCCESS
       } catch (e: Exception) {
-        EXIT_CODE_FAILURE
+        e.printStackTrace(err)
+        return EXIT_CODE_FAILURE
       }
     }
 
@@ -99,13 +106,14 @@ class Main(
       return EXIT_CODE_FAILURE
     }
 
-    val retval = AtomicInteger(0)
+    val retval = AtomicInteger(EXIT_CODE_SUCCESS)
     files.parallelStream().forEach {
       try {
         if (!format(it, parsedArgs) && parsedArgs.setExitIfChanged) {
           retval.set(EXIT_CODE_FAILURE)
         }
       } catch (e: Exception) {
+        e.printStackTrace(err)
         retval.set(EXIT_CODE_FAILURE)
       }
     }

From 73563a63f49a5573abe789eebf8640fed2e7dc1d Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Mon, 10 Jun 2024 17:22:03 +0100
Subject: [PATCH 6/9] Use constant for CLI usage string

---
 core/src/main/java/com/facebook/ktfmt/cli/Main.kt | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index ace92ca0..f2de4899 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -36,6 +36,10 @@ private const val EXIT_CODE_FAILURE = 1
 
 private const val EXIT_CODE_SUCCESS = 0
 
+private const val USAGE =
+    """Usage: ktfmt [--style=dropbox|google|kotlinlang] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...
+Or: ktfmt @file"""
+
 class Main(
     private val input: InputStream,
     private val out: PrintStream,
@@ -80,8 +84,7 @@ class Main(
           }
         }
     if (parsedArgs.fileNames.isEmpty()) {
-      err.println(
-          "Usage: ktfmt [--style=dropbox|google|kotlinlang] [--dry-run] [--set-exit-if-changed] [--stdin-name=<name>] [--do-not-remove-unused-imports] File1.kt File2.kt ...\nOr: ktfmt @file")
+      err.println(USAGE)
       return EXIT_CODE_FAILURE
     }
 

From 9e65203bafc34742c86fc1c1bde1ec01c9ccad64 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Mon, 10 Jun 2024 17:24:53 +0100
Subject: [PATCH 7/9] Remove exitFatal() from CLI

The tests in MainTest.kt will fail since the JVM is terminated by the
exitProcess() call. In addition, many of the tests want to check the
return code so exiting directly is a bad idea.
---
 core/src/main/java/com/facebook/ktfmt/cli/Main.kt | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index f2de4899..3b2dd403 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -179,15 +179,4 @@ class Main(
       throw e
     }
   }
-
-  /**
-   * Finishes the process with result `returnCode`.
-   *
-   * **WARNING**: If you call this method, this is the last that will happen and no code after it
-   * will be executed.
-   */
-  private fun exitFatal(message: String, returnCode: Int): Nothing {
-    err.println(message)
-    exitProcess(returnCode)
-  }
 }

From 64a7d8a9080780e19399052f798e5dba1d5cd7d3 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Mon, 10 Jun 2024 17:25:02 +0100
Subject: [PATCH 8/9] Clean up

---
 core/src/main/java/com/facebook/ktfmt/cli/Main.kt | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index 3b2dd403..5fb2dcd6 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -90,15 +90,15 @@ class Main(
 
     if (parsedArgs.fileNames.size == 1 && parsedArgs.fileNames[0] == "-") {
       // Format code read from stdin
-      try {
+      return try {
         val alreadyFormatted = format(null, parsedArgs)
-        return if (!alreadyFormatted && parsedArgs.setExitIfChanged)
-          EXIT_CODE_FAILURE
+        if (!alreadyFormatted && parsedArgs.setExitIfChanged)
+            EXIT_CODE_FAILURE
         else
-          EXIT_CODE_SUCCESS
+            EXIT_CODE_SUCCESS
       } catch (e: Exception) {
         e.printStackTrace(err)
-        return EXIT_CODE_FAILURE
+        EXIT_CODE_FAILURE
       }
     }
 

From 31347fd4dda471a6d4372bca1616fc5fede06c30 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Mon, 10 Jun 2024 20:50:37 +0100
Subject: [PATCH 9/9] Revert "Use --style=<style> in CLI"

This reverts commit b2e59446fed0ef8f1f7f76d4aa4e3b5e1ce0c4b0.
---
 .../main/java/com/facebook/ktfmt/cli/Main.kt  |  2 +-
 .../java/com/facebook/ktfmt/cli/ParsedArgs.kt | 22 ++++------------
 .../java/com/facebook/ktfmt/cli/MainTest.kt   |  4 +--
 .../com/facebook/ktfmt/cli/ParsedArgsTest.kt  | 26 +++++--------------
 4 files changed, 15 insertions(+), 39 deletions(-)

diff --git a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
index 5fb2dcd6..bcd703b0 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/Main.kt
@@ -103,7 +103,7 @@ class Main(
     }
 
     val files: List<File> = expandArgsToFileNames(parsedArgs.fileNames)
-
+    
     if (files.isEmpty()) {
       err.println("Error: no .kt files found")
       return EXIT_CODE_FAILURE
diff --git a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
index 60cc4498..b443afea 100644
--- a/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
+++ b/core/src/main/java/com/facebook/ktfmt/cli/ParsedArgs.kt
@@ -59,19 +59,9 @@ data class ParsedArgs(
 
       for (arg in args) {
         when {
-          arg.startsWith("--style=") -> {
-            val parsedStyle =
-                parseKeyValueArg("--style", arg) ?: return ParseResult.Error(unexpectedArg(arg))
-            formattingOptions =
-                when (parsedStyle) {
-                  "dropbox" -> Formatter.DROPBOX_FORMAT
-                  "google" -> Formatter.GOOGLE_FORMAT
-                  "kotlinlang" -> Formatter.KOTLINLANG_FORMAT
-                  else ->
-                      return ParseResult.Error(
-                          "Unknown style '${parsedStyle}'. Style must be one of [dropbox, google, kotlinlang].")
-                }
-          }
+          arg == "--dropbox-style" -> formattingOptions = Formatter.DROPBOX_FORMAT
+          arg == "--google-style" -> formattingOptions = Formatter.GOOGLE_FORMAT
+          arg == "--kotlinlang-style" -> formattingOptions = Formatter.KOTLINLANG_FORMAT
           arg == "--dry-run" || arg == "-n" -> dryRun = true
           arg == "--set-exit-if-changed" -> setExitIfChanged = true
           arg == "--do-not-remove-unused-imports" -> removeUnusedImports = false
@@ -80,8 +70,8 @@ data class ParsedArgs(
                   parseKeyValueArg("--stdin-name", arg)
                       ?: return ParseResult.Error(
                           "Found option '${arg}', expected '${"--stdin-name"}=<value>'")
-          arg.startsWith("--") -> return ParseResult.Error(unexpectedArg(arg))
-          arg.startsWith("@") -> return ParseResult.Error(unexpectedArg(arg))
+          arg.startsWith("--") -> return ParseResult.Error("Unexpected option: $arg")
+          arg.startsWith("@") -> return ParseResult.Error("Unexpected option: $arg")
           else -> fileNames.add(arg)
         }
       }
@@ -108,8 +98,6 @@ data class ParsedArgs(
           ))
     }
 
-    private fun unexpectedArg(arg: String) = "Unexpected option: $arg"
-
     private fun parseKeyValueArg(key: String, arg: String): String? {
       val parts = arg.split('=', limit = 2)
       return parts[1].takeIf { parts[0] == key || parts.size == 2 }
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
index d9432ddf..21c980ec 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/MainTest.kt
@@ -244,7 +244,7 @@ class MainTest {
             emptyInput,
             PrintStream(out),
             PrintStream(err),
-            arrayOf("--style=dropbox", fooBar.toString()))
+            arrayOf("--dropbox-style", fooBar.toString()))
         .run()
 
     assertThat(fooBar.readText()).isEqualTo(code)
@@ -274,7 +274,7 @@ class MainTest {
             code.byteInputStream(),
             PrintStream(out),
             PrintStream(err),
-            arrayOf("--style=dropbox", "-"))
+            arrayOf("--dropbox-style", "-"))
         .run()
 
     assertThat(out.toString(UTF_8)).isEqualTo(formatted)
diff --git a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
index 17dc6353..7b81b1b9 100644
--- a/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
+++ b/core/src/test/java/com/facebook/ktfmt/cli/ParsedArgsTest.kt
@@ -61,29 +61,17 @@ class ParsedArgsTest {
   }
 
   @Test
-  fun `parseOptions recognizes --style=dropbox`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--style=dropbox", "foo.kt")))
+  fun `parseOptions recognizes --dropbox-style`() {
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--dropbox-style", "foo.kt")))
     assertThat(parsed.formattingOptions).isEqualTo(Formatter.DROPBOX_FORMAT)
   }
 
   @Test
-  fun `parseOptions recognizes --style=google`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--style=google", "foo.kt")))
+  fun `parseOptions recognizes --google-style`() {
+    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--google-style", "foo.kt")))
     assertThat(parsed.formattingOptions).isEqualTo(Formatter.GOOGLE_FORMAT)
   }
 
-  @Test
-  fun `parseOptions recognizes --style=kotlinlang`() {
-    val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--style=kotlinlang", "foo.kt")))
-    assertThat(parsed.formattingOptions).isEqualTo(Formatter.KOTLINLANG_FORMAT)
-  }
-
-  @Test
-  fun `parseOptions rejects unknown style`() {
-    val parseResult = ParsedArgs.parseOptions(arrayOf("--style=custom-style", "foo.kt"))
-    assertThat(parseResult).isInstanceOf(ParseResult.Error::class.java)
-  }
-
   @Test
   fun `parseOptions recognizes --dry-run`() {
     val parsed = assertSucceeds(ParsedArgs.parseOptions(arrayOf("--dry-run", "foo.kt")))
@@ -157,7 +145,7 @@ class ParsedArgsTest {
   @Test
   fun `processArgs use the @file option with file containing arguments`() {
     val file = root.resolve("existing-file")
-    file.writeText("--style=google\n--dry-run\n--set-exit-if-changed\nFile1.kt\nFile2.kt\n")
+    file.writeText("--google-style\n--dry-run\n--set-exit-if-changed\nFile1.kt\nFile2.kt\n")
 
     val result = ParsedArgs.processArgs(arrayOf("@" + file.absolutePath))
     assertThat(result).isInstanceOf(ParseResult.Ok::class.java)
@@ -174,7 +162,7 @@ class ParsedArgsTest {
   fun `parses multiple args successfully`() {
     val testResult =
         ParsedArgs.parseOptions(
-            arrayOf("--style=google", "--dry-run", "--set-exit-if-changed", "File.kt"),
+            arrayOf("--google-style", "--dry-run", "--set-exit-if-changed", "File.kt"),
         )
     assertThat(testResult)
         .isEqualTo(
@@ -189,7 +177,7 @@ class ParsedArgsTest {
   @Test
   fun `last style in args wins`() {
     val testResult =
-        ParsedArgs.parseOptions(arrayOf("--style=google", "--style=dropbox", "File.kt"))
+        ParsedArgs.parseOptions(arrayOf("--google-style", "--dropbox-style", "File.kt"))
     assertThat(testResult)
         .isEqualTo(
             parseResultOk(