Add new fromClosestTag function (#68)

README.md

@@ -66,6 +66,18 @@ const state = isDirty();
 console.log(state); // false
 ```
 
+### Commits away from closest tag
+
+Get the number of commits from the closest tagged commit to the current HEAD commit.
+
+```js
+import { fromClosestTag } from 'git-ref';
+
+const count = fromClosestTag();
+
+console.log(count); // 0
+```
+
 ## Changelog
 
 See [releases on GitHub](https://github.com/maxmilton/git-ref/releases).

src/index.ts

@@ -1,3 +1,5 @@
+/* eslint-disable no-console */
+
 import { execSync } from 'child_process';
 
 /**
@@ -16,7 +18,6 @@ export function gitRef(cwd?: string): string {
     });
     reference = result.toString().trim();
   } catch (error) {
-    // eslint-disable-next-line no-console
     console.error(error);
   }
 
@@ -32,7 +33,7 @@ export default gitRef;
  * the first 7 characters (default `false`).
  * @param cwd - Modify the working directory git is executed in (default is the
  * directory of the current node process).
- * @returns The git commit hash.
+ * @returns A git commit hash.
  */
 export function gitHash(long?: boolean, cwd?: string): string {
   let hash = '';
@@ -43,7 +44,6 @@ export function gitHash(long?: boolean, cwd?: string): string {
     });
     hash = result.toString().trim();
   } catch (error) {
-    // eslint-disable-next-line no-console
     console.error(error);
   }
 
@@ -64,9 +64,33 @@ export function isDirty(cwd?: string): boolean {
     const result = execSync('git status --porcelain', { cwd });
     dirty = !!result.toString().trim();
   } catch (error) {
-    // eslint-disable-next-line no-console
     console.error(error);
   }
 
   return dirty;
 }
+
+/**
+ * Get the number of commits from the closest tagged commit to the HEAD commit.
+ *
+ * Note: Unix only due to shell command substitution.
+ *
+ * @param cwd - Modify the working directory git is executed in (default is the
+ * directory of the current node process).
+ * @returns The number of commits from closest tag to HEAD or -1 when error.
+ */
+export function fromClosestTag(cwd?: string): number {
+  let count = -1;
+
+  try {
+    const result = execSync(
+      'git rev-list $(git describe --abbrev=0)..HEAD --count',
+      { cwd },
+    );
+    count = +result.toString().trim();
+  } catch (error) {
+    console.error(error);
+  }
+
+  return count;
+}

test/index.test.ts

@@ -1,6 +1,8 @@
 import * as assert from 'uvu/assert';
 import * as allExports from '../src/index';
-import { gitHash, gitRef, isDirty } from '../src/index';
+import {
+  fromClosestTag, gitHash, gitRef, isDirty,
+} from '../src/index';
 import {
   createTempDir,
   deleteTempDir,
@@ -16,6 +18,7 @@ describe('exports', (test) => {
       ['gitRef', '"gitRef" named'],
       ['gitHash', '"gitHash" named'],
       ['isDirty', '"isDirty" named'],
+      ['fromClosestTag', '"fromClosestTag" named'],
     ] as const
   ).forEach(([name, description]) => {
     test(`has a ${description} export`, () => {
@@ -288,3 +291,116 @@ describe('isDirty', (test) => {
     assert.is(result4, false);
   });
 });
+
+describe('fromClosestTag', (test) => {
+  test.before(createTempDir);
+  test.after(deleteTempDir);
+
+  test('returns -1 in non-git dir', () => {
+    const dir = getTempDir('not-git');
+    const result = fromClosestTag(dir);
+    assert.is(result, -1);
+  });
+
+  test('returns -1 in repo without commits', () => {
+    const dir = getTempDir('no-commit');
+    execCmds(dir, ['git init --quiet']);
+    const result = fromClosestTag(dir);
+    assert.is(result, -1);
+  });
+
+  test('returns -1 in repo with uncommitted new file', () => {
+    const dir = getTempDir('uncommitted-file');
+    execCmds(dir, ['git init --quiet', 'touch file.txt']);
+    const result = fromClosestTag(dir);
+    assert.is(result, -1);
+  });
+
+  test('returns 0 in repo with no tags', () => {
+    const dir = getTempDir('with-commit');
+    execCmds(dir, [
+      'git init --quiet',
+      'git config user.email "test@test.com"',
+      'git config user.name "Test Test"',
+      'touch file1.txt',
+      'git add file1.txt',
+      'git commit --quiet --no-gpg-sign -m "commit1"',
+    ]);
+    const result1 = fromClosestTag(dir);
+    assert.type(result1, 'number');
+    assert.is(result1, 0);
+    execCmds(dir, [
+      'touch file2.txt',
+      'git add file2.txt',
+      'git commit --quiet --no-gpg-sign -m "commit2"',
+    ]);
+    const result2 = fromClosestTag(dir);
+    assert.type(result2, 'number');
+    assert.is(result2, 0);
+    execCmds(dir, [
+      'touch file3.txt',
+      'git add file3.txt',
+      'git commit --quiet --no-gpg-sign -m "commit3"',
+    ]);
+    const result3 = fromClosestTag(dir);
+    assert.type(result3, 'number');
+    assert.is(result3, 0);
+  });
+
+  test('returns count in repo with commits after tag', () => {
+    const dir = getTempDir('tag-commits');
+    execCmds(dir, [
+      'git init --quiet',
+      'git config user.email "test@test.com"',
+      'git config user.name "Test Test"',
+      'touch file1.txt',
+      'git add file1.txt',
+      'git commit --quiet --no-gpg-sign -m "commit1"',
+    ]);
+    const result1 = fromClosestTag(dir);
+    assert.type(result1, 'number');
+    assert.is(result1, 0);
+    execCmds(dir, [
+      'touch file2.txt',
+      'git add file2.txt',
+      'git commit --quiet --no-gpg-sign -m "commit2"',
+      'git tag --no-sign -m "v1" v1',
+    ]);
+    const result2 = fromClosestTag(dir);
+    assert.type(result2, 'number');
+    assert.is(result2, 0);
+    execCmds(dir, [
+      'touch file3.txt',
+      'git add file3.txt',
+      'git commit --quiet --no-gpg-sign -m "commit3"',
+    ]);
+    const result3 = fromClosestTag(dir);
+    assert.type(result3, 'number');
+    assert.is(result3, 1);
+    execCmds(dir, [
+      'touch file4.txt',
+      'git add file4.txt',
+      'git commit --quiet --no-gpg-sign -m "commit4"',
+    ]);
+    const result4 = fromClosestTag(dir);
+    assert.type(result4, 'number');
+    assert.is(result4, 2);
+    execCmds(dir, [
+      'touch file5.txt',
+      'git add file5.txt',
+      'git commit --quiet --no-gpg-sign -m "commit5"',
+      'git tag --no-sign -m "v2" v2',
+    ]);
+    const result5 = fromClosestTag(dir);
+    assert.type(result5, 'number');
+    assert.is(result5, 0);
+    execCmds(dir, [
+      'touch file6.txt',
+      'git add file6.txt',
+      'git commit --quiet --no-gpg-sign -m "commit6"',
+    ]);
+    const result6 = fromClosestTag(dir);
+    assert.type(result6, 'number');
+    assert.is(result6, 1);
+  });
+});