Fix wrapping of expression body when max_line_length not set (#2833)

This fixes the wrapping of the expression for code style `intellij_idea` which does not set the `max_line_length` property by default. But it also fixes the wrapping in case the `max_line_length` property contains value `unset` for any of the code styles.

Closes #2827

ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/FunctionSignatureRule.kt

@@ -240,6 +240,7 @@ public class FunctionSignatureRule :
  } else {
  fixWhiteSpacesInValueParameterList(node, emit, multiline = true, dryRun = false)
  }
+ fixFunctionBodyExpression(node, emit, MAX_LINE_LENGTH_PROPERTY_OFF)
  }
  }
 

ktlint-ruleset-standard/src/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/FunctionSignatureRuleTest.kt

@@ -8,6 +8,7 @@ import com.pinterest.ktlint.ruleset.standard.StandardRuleSetProvider
 import com.pinterest.ktlint.ruleset.standard.rules.FunctionSignatureRule.Companion.FORCE_MULTILINE_WHEN_PARAMETER_COUNT_GREATER_OR_EQUAL_THAN_PROPERTY
 import com.pinterest.ktlint.ruleset.standard.rules.FunctionSignatureRule.Companion.FUNCTION_BODY_EXPRESSION_WRAPPING_PROPERTY
 import com.pinterest.ktlint.ruleset.standard.rules.FunctionSignatureRule.FunctionBodyExpressionWrapping
+import com.pinterest.ktlint.ruleset.standard.rules.FunctionSignatureRule.FunctionBodyExpressionWrapping.always
 import com.pinterest.ktlint.ruleset.standard.rules.FunctionSignatureRule.FunctionBodyExpressionWrapping.default
 import com.pinterest.ktlint.test.KtLintAssertThat.Companion.EOL_CHAR
 import com.pinterest.ktlint.test.KtLintAssertThat.Companion.MAX_LINE_LENGTH_MARKER
@@ -743,14 +744,8 @@ class FunctionSignatureRuleTest {
  .hasNoLintViolations()
  }
 
- @ParameterizedTest(name = "bodyExpressionWrapping: {0}")
- @EnumSource(
- value = FunctionBodyExpressionWrapping::class,
- names = ["always"],
- )
- fun `Given that the function signature and a single line body expression body fit on the same line then do not reformat function signature but move the body expression to a separate line`(
- bodyExpressionWrapping: FunctionBodyExpressionWrapping,
- ) {
+ @Test
+ fun `Given that the function signature and a single line body expression body fit on the same line then do not reformat function signature but move the body expression to a separate line`() {
  val code =
  """
  // $MAX_LINE_LENGTH_MARKER $EOL_CHAR
@@ -765,12 +760,35 @@ class FunctionSignatureRuleTest {
  functionSignatureWrappingRuleAssertThat(code)
  .setMaxLineLength()
  .withEditorConfigOverride(FORCE_MULTILINE_WHEN_PARAMETER_COUNT_GREATER_OR_EQUAL_THAN_PROPERTY to "unset")
- .withEditorConfigOverride(FUNCTION_BODY_EXPRESSION_WRAPPING_PROPERTY to bodyExpressionWrapping)
+ .withEditorConfigOverride(FUNCTION_BODY_EXPRESSION_WRAPPING_PROPERTY to always)
  .addAdditionalRuleProvider { IndentationRule() }
  .hasLintViolation(2, 33, "Newline expected before expression body")
  .isFormattedAs(formattedCode)
  }
 
+ @ParameterizedTest(name = "code style: {0}")
+ @EnumSource(value = CodeStyleValue::class)
+ fun `Issue 2827 - Given that no max_line_length set, and the function signature is a single line body expression body that does fit on the same line then wrap the body expression to a separate line`(
+ codeStyleValue: CodeStyleValue,
+ ) {
+ val code =
+ """
+ fun f(a: Any, b: Any): String = "some-result"
+ """.trimIndent()
+ val formattedCode =
+ """
+ fun f(a: Any, b: Any): String =
+ "some-result"
+ """.trimIndent()
+ functionSignatureWrappingRuleAssertThat(code)
+ .withEditorConfigOverride(CODE_STYLE_PROPERTY to codeStyleValue)
+ .withEditorConfigOverride(FORCE_MULTILINE_WHEN_PARAMETER_COUNT_GREATER_OR_EQUAL_THAN_PROPERTY to "unset")
+ .withEditorConfigOverride(FUNCTION_BODY_EXPRESSION_WRAPPING_PROPERTY to always)
+ .addAdditionalRuleProvider { IndentationRule() }
+ .hasLintViolation(1, 33, "Newline expected before expression body")
+ .isFormattedAs(formattedCode)
+ }
+
  @ParameterizedTest(name = "bodyExpressionWrapping: {0}")
  @EnumSource(
  value = FunctionBodyExpressionWrapping::class,