feat: 新增 dedent

src/index.ts

@@ -1,6 +1,7 @@
 export * from 'lodash-es'
 
 // @index(['./**/*.ts', '!./**/*.test.*'], f => `export * from '${f.path}'`)
+export * from './utils/dedent'
 export * from './utils/EventBus'
 export * from './utils/indent'
 export * from './utils/isPossibleChineseMobilePhoneNumber'

src/utils/dedent.test.ts

@@ -0,0 +1,62 @@
+import { dedent } from './dedent'
+import { indent } from './indent'
+
+describe(dedent.name, () => {
+  test('空字符串正常', () => {
+    expect(dedent``).toBe('')
+  })
+
+  test('单行字符串', () => {
+    expect(dedent`hello`).toBe('hello')
+  })
+
+  test('有缩进的多行字符串', () => {
+    expect(dedent` hello\n  world`).toBe('hello\n world')
+  })
+
+  test('首尾存在换行符的多行字符串', () => {
+    expect(dedent`
+      ${'  '}
+      hello
+
+      world
+        ---
+
+    `).toBe('hello\n\nworld\n  ---')
+  })
+
+  test('杂项 1', () => {
+    const x = dedent`
+      String literal, provides the branch for the current build.
+      @example
+      \`\`\`sh
+      DRONE_COMMIT_BRANCH=master
+      \`\`\`
+    `
+    const y = dedent`${indent`
+      String literal, provides the branch for the current build.
+      @example
+      \`\`\`sh
+      DRONE_COMMIT_BRANCH=master
+      \`\`\`
+    `}`
+    expect(x).toBe(y)
+  })
+
+  test('杂项 2', () => {
+    const t = dedent`
+      d
+      e
+    `
+    const x = dedent`
+      a
+      b
+
+      c
+
+      ${t}
+    `
+    const y = 'a\nb\n\nc\n\nd\ne'
+    expect(x).toBe(y)
+  })
+})

src/utils/dedent.ts

@@ -0,0 +1,54 @@
+import { indent } from './indent'
+
+/**
+ * 首先，每一行紧跟前导空白的插入值为多行时，保持缩进。
+ * 然后，移除每一行的公共前导空白。
+ *
+ * ```
+ * dedent` a\n b` // => 'a\nb'
+ * ```
+ *
+ * @param literals 字面值
+ * @param interpolations 插入值
+ * @returns 返回处理后的结果
+ */
+export function dedent(
+  literals: TemplateStringsArray,
+  ...interpolations: string[]
+): string {
+  const text = indent(literals, ...interpolations)
+
+  // 公共的前导空白
+  let commonLeadingWhitespace!: string
+  // 第一个非空行
+  let firstLineIndex!: number
+  // 最后一个非空行
+  let lastLineIndex!: number
+
+  const lines = text.split(/[\r\n]/g)
+
+  for (let index = 0; index < lines.length; index++) {
+    // 当前行的前导空白
+    const leadingWhitespace = lines[index].match(/^\s*/)![0]
+    // 如果当前行的前导空白等于当前行的长度，则认为这是一个空行，跳过
+    if (leadingWhitespace.length !== lines[index].length) {
+      lastLineIndex = index
+      if (firstLineIndex == null) {
+        firstLineIndex = index
+      }
+      if (
+        commonLeadingWhitespace == null ||
+        leadingWhitespace.length < commonLeadingWhitespace.length
+      ) {
+        commonLeadingWhitespace = leadingWhitespace
+      }
+    }
+  }
+
+  return commonLeadingWhitespace == null
+    ? text
+    : lines
+        .slice(firstLineIndex, lastLineIndex + 1)
+        .map(line => line.substr(commonLeadingWhitespace.length))
+        .join('\n')
+}