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Nivaldo Bondançafacebook-github-bot
Nivaldo Bondança
authored and
facebook-github-bot
committed
trimMargin and trimIndent formatting
Summary: Just because it's a multiline string it doesn't mean it doesn't have to be properly formatted. Following the popular opinion from here https://fb.workplace.com/groups/ktfmt/posts/2287111725069697 Reviewed By: cortinico Differential Revision: D79772886 fbshipit-source-id: 77241b451e36b336cf43d1652fca3d6e228c41c8
1 parent c974608 commit e14d99c

4 files changed

Lines changed: 286 additions & 3 deletions

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‎CHANGELOG.md‎

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@@ -15,6 +15,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
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### Added
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- `TrailingCommaManagementStrategy.ONLY_ADD` strategy that does not remove existing trailing commas (https://github.com/facebook/ktfmt/issues/461, https://github.com/facebook/ktfmt/issues/512, https://github.com/facebook/ktfmt/issues/514)
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- Formatting of where clauses (https://github.com/facebook/ktfmt/issues/541)
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- Special format handling of multiline strings with `trimMargin()` and `trimIndent` (https://github.com/facebook/ktfmt/issues/389)
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### Changed
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- `FormattingOptions.manageTrailingCommas` was replaced with `FormattingOptions.trailingCommaManagementStrategy`, which also added new `TrailingCommaManagementStrategy.ONLY_ADD` strategy (https://github.com/facebook/ktfmt/issues/461, https://github.com/facebook/ktfmt/issues/512, https://github.com/facebook/ktfmt/issues/514)

‎core/src/main/java/com/facebook/ktfmt/format/Formatter.kt‎

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@@ -102,8 +102,9 @@ object Formatter {
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.let { convertLineSeparators(it) }
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.let { sortedAndDistinctImports(it) }
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.let { dropRedundantElements(it, options) }
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.let { prettyPrint(it, options, "\n") }
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.let { prettyPrint(it, options, lineSeparator = "\n") }
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.let { addRedundantElements(it, options) }
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.let { MultilineStringFormatter(options.continuationIndent).format(it) }
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.let { convertLineSeparators(it, checkNotNull(Newlines.guessLineSeparator(kotlinCode))) }
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.let { if (shebang.isEmpty()) it else shebang + "\n" + it }
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}

‎core/src/main/java/com/facebook/ktfmt/format/MultilineStringFormatter.kt‎

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@@ -0,0 +1,131 @@
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/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.facebook.ktfmt.format
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import org.jetbrains.kotlin.psi.KtQualifiedExpression
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import org.jetbrains.kotlin.psi.KtStringTemplateExpression
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import org.jetbrains.kotlin.psi.KtTreeVisitorVoid
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import org.jetbrains.kotlin.psi.psiUtil.startOffset
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/**
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* Adds and removes elements that are not strictly needed in the code, such as semicolons and unused
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* imports.
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*/
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class MultilineStringFormatter(val continuationIndentSize: Int) {
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class Candidate(
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val isMargin: Boolean,
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/* The start offset of the trim method call, right before `.trimX` */
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val trimMethodCallOffset: Int,
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/* The start offset of the string template, starting with `"""` or `$$"""` */
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val stringOffset: Int,
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) {
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val indentationSuffix: String = if (isMargin) "|" else ""
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}
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companion object {
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private const val TQ = "\"\"\""
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}
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private val String.indentLevel: Int
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get() = length - trimStart().length
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fun format(code: String): String {
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val candidates = getCandidates(code)
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val result = StringBuilder(code)
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for (candidate in candidates.sortedByDescending(Candidate::stringOffset)) {
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val (indentCount, lines) =
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result.substring(candidate.stringOffset, candidate.trimMethodCallOffset).lines().let {
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result.substring(0, candidate.stringOffset).lines().last().length to it.dropLast(1)
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}
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if (lines.size < 2) {
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// Single line multiline strings are left alone
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continue
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}
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val indentation = " ".repeat(indentCount)
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val continuationIndentation = " ".repeat(continuationIndentSize)
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val minIndentForTrimIndent: Int =
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lines.subList(1, lines.size).minOf { if (it.isEmpty()) Int.MAX_VALUE else it.indentLevel }
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val multiline = StringBuilder()
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lines.forEachIndexed { i, line ->
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if (i == 0) {
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val (before, after) = line.split(TQ, limit = 2)
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if (after.isNotEmpty()) {
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multiline.append(before)
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multiline.appendLine(TQ)
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multiline.append(indentation)
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multiline.append(candidate.indentationSuffix)
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multiline.appendLine(after)
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} else {
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multiline.appendLine(line)
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}
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} else {
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val lineContents =
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if (candidate.isMargin) {
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if (i == lines.lastIndex && "|" !in line && line.substringBefore(TQ).isBlank()) {
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// trimMargin has a special handling of the final line, where it ignores it if
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// it's blank
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// Drop last new line character
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multiline.deleteAt(multiline.lastIndex)
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multiline.appendLine(line.substring(line.indexOf(TQ)))
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return@forEachIndexed
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}
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line.substringAfter("|")
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} else {
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line.drop(minIndentForTrimIndent)
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}
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if (candidate.isMargin || line.isNotEmpty()) {
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multiline.append(indentation)
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}
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multiline.append(candidate.indentationSuffix)
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multiline.appendLine(lineContents)
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}
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}
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multiline.append(indentation)
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multiline.append(continuationIndentation)
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result.replace(candidate.stringOffset, candidate.trimMethodCallOffset, multiline.toString())
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}
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return result.toString()
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}
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private fun getCandidates(code: String): List<Candidate> {
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val file = Parser.parse(code)
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val candidates = mutableListOf<Candidate>()
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file.accept(
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object : KtTreeVisitorVoid() {
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override fun visitQualifiedExpression(expression: KtQualifiedExpression) {
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val receiver = expression.receiverExpression
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if (receiver !is KtStringTemplateExpression) return
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val selectorExpression = expression.selectorExpression?.text.orEmpty().trim()
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val isTrimMargin = selectorExpression.startsWith("trimMargin(")
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val isTrimIndent = selectorExpression.startsWith("trimIndent(")
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if (isTrimIndent || isTrimMargin) {
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// -1 here to account for the space after the dot
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val trimOffset = checkNotNull(expression.selectorExpression).startOffset - 1
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val stringOffset = receiver.startOffset
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candidates.add(Candidate(isTrimMargin, trimOffset, stringOffset))
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}
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}
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})
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return candidates
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}
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}

‎core/src/test/java/com/facebook/ktfmt/format/FormatterTest.kt‎

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@@ -1602,7 +1602,7 @@ class FormatterTest {
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Env.Prod,
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)
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val aVar = setOf(Env.Dev, Env.Prod)
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16061606
"""
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.trimIndent(),
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deduceMaxWidth = false,
@@ -2973,6 +2973,156 @@ class FormatterTest {
29732973
|"""
29742974
.trimMargin())
29752975

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@Test
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fun `multiline trimMargin special handling`() {
2978+
val before =
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"""
2980+
|val margin =
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| ${TQ}example
2982+
| | of
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| | a
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| |multiline
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| | string
2986+
| |$TQ
2987+
| .trimMargin()
2988+
|"""
2989+
.trimMargin()
2990+
val after =
2991+
"""
2992+
|val margin =
2993+
| $TQ
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| |example
2995+
| | of
2996+
| | a
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| |multiline
2998+
| | string
2999+
| |$TQ
3000+
| .trimMargin()
3001+
|"""
3002+
.trimMargin()
3003+
3004+
assertThatFormatting(before).isEqualTo(after)
3005+
}
3006+
3007+
@Test
3008+
fun `multiline trimIndent special handling`() {
3009+
val before =
3010+
"""
3011+
|val indent =
3012+
| ${TQ}example
3013+
| of
3014+
| a
3015+
|
3016+
| multiline
3017+
| string
3018+
| $TQ
3019+
| .trimIndent()
3020+
|"""
3021+
.trimMargin()
3022+
val after =
3023+
"""
3024+
|val indent =
3025+
| $TQ
3026+
| example
3027+
| of
3028+
| a
3029+
|
3030+
| multiline
3031+
| string
3032+
| $TQ
3033+
| .trimIndent()
3034+
|"""
3035+
.trimMargin()
3036+
3037+
assertThatFormatting(before).isEqualTo(after)
3038+
}
3039+
3040+
@Test
3041+
fun `trimIndent and trimMargin formatting does not add new lines`() {
3042+
assertThatFormatting(
3043+
"""
3044+
|val margin =
3045+
| $TQ
3046+
| |is this the end of the line?$TQ
3047+
| .trimMargin()
3048+
|"""
3049+
.trimMargin())
3050+
.isEqualTo(
3051+
"""
3052+
|val margin =
3053+
| $TQ
3054+
| |is this the end of the line?$TQ
3055+
| .trimMargin()
3056+
|"""
3057+
.trimMargin())
3058+
3059+
assertThatFormatting(
3060+
"""
3061+
|val margin =
3062+
| $TQ
3063+
| is this the end of the line?$TQ
3064+
| .trimIndent()
3065+
|"""
3066+
.trimMargin())
3067+
.isEqualTo(
3068+
"""
3069+
|val margin =
3070+
| $TQ
3071+
| is this the end of the line?$TQ
3072+
| .trimIndent()
3073+
|"""
3074+
.trimMargin())
3075+
}
3076+
3077+
@Test
3078+
fun `properly handles trimMargin blank lines at the end of multiline string`() =
3079+
assertThatFormatting(
3080+
"""
3081+
|val margin =
3082+
| $TQ
3083+
| |test
3084+
| string
3085+
| |
3086+
| $TQ
3087+
| .trimMargin()
3088+
|"""
3089+
.trimMargin())
3090+
.isEqualTo(
3091+
"""
3092+
|val margin =
3093+
| $TQ
3094+
| |test
3095+
| | string
3096+
| |$TQ
3097+
| .trimMargin()
3098+
|"""
3099+
.trimMargin())
3100+
3101+
@Test
3102+
fun `handles multi-dollar string`() =
3103+
assertThatFormatting(
3104+
"""
3105+
|val margin =
3106+
| ${"$$"}$TQ
3107+
| |{
3108+
| "${'$'}test": "string"
3109+
| |}
3110+
|
3111+
| $TQ.trimMargin()
3112+
|"""
3113+
.trimMargin())
3114+
.isEqualTo(
3115+
"""
3116+
|val margin =
3117+
| ${"$$"}$TQ
3118+
| |{
3119+
| | "${'$'}test": "string"
3120+
| |}
3121+
| |$TQ
3122+
| .trimMargin()
3123+
|"""
3124+
.trimMargin())
3125+
29763126
@Test
29773127
fun `Trailing spaces in a comment are not preserved`() {
29783128
val before =
@@ -7799,7 +7949,7 @@ class FormatterTest {
77997949
| is Animal.Dog -> animal.feedDog()
78007950
| is Animal.Cat if !animal.mouseHunter -> animal.feedCat()
78017951
| is Animal.Cat if !animal.birdHunter -> animal.feedCat()
7802-
| is Animal.Cat if
7952+
| is Animal.Cat if
78037953
| !animal.birdHunter -> animal.feedCat()
78047954
| is Animal.Cat if (!animal.birdHunter) -> animal.feedCat()
78057955
| else -> println("Unknown animal")

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