From 7c35a842a6cba3f1344a09800626cce204120bf4 Mon Sep 17 00:00:00 2001
From: flouc001 <flouc001@gmail.com>
Date: Sat, 11 Jul 2020 09:24:46 +0100
Subject: [PATCH 1/6] add dry run capabilities to default slugger

---
 src/Slugger.js           | 42 ++++++++++++++++++++++++++++++----------
 test/unit/marked-spec.js |  6 ++++++
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/src/Slugger.js b/src/Slugger.js
index 7095454ac3..75e16c85a3 100644
--- a/src/Slugger.js
+++ b/src/Slugger.js
@@ -6,11 +6,8 @@ module.exports = class Slugger {
     this.seen = {};
   }
 
-  /**
-   * Convert string to unique id
-   */
-  slug(value) {
-    let slug = value
+  serialize(value) {
+    return value
       .toLowerCase()
       .trim()
       // remove html tags
@@ -18,16 +15,41 @@ module.exports = class Slugger {
       // remove unwanted chars
       .replace(/[\u2000-\u206F\u2E00-\u2E7F\\'!"#$%&()*+,./:;<=>?@[\]^`{|}~]/g, '')
       .replace(/\s/g, '-');
+  }
 
+  /**
+   * Finds the next safe (unique) slug to use
+   */
+  getNextSafeSlug(originalSlug, isDryRun) {
+    let slug = originalSlug;
+    let occurenceAccumulator = 0;
     if (this.seen.hasOwnProperty(slug)) {
-      const originalSlug = slug;
+      occurenceAccumulator = this.seen[originalSlug];
       do {
-        this.seen[originalSlug]++;
-        slug = originalSlug + '-' + this.seen[originalSlug];
+        occurenceAccumulator++;
+        slug = originalSlug + '-' + occurenceAccumulator;
       } while (this.seen.hasOwnProperty(slug));
     }
-    this.seen[slug] = 0;
-
+    if (!isDryRun) {
+      this.seen[originalSlug] = occurenceAccumulator;
+      this.seen[slug] = 0;
+    }
     return slug;
   }
+
+  /**
+   * Convert string to unique id
+   */
+  slug(value) {
+    const slug = this.serialize(value);
+    return this.getNextSafeSlug(slug);
+  }
+
+  /**
+   * Get slug text without incrementing accumulator
+   */
+  slugText(value) {
+    const slug = this.serialize(value);
+    return this.getNextSafeSlug(slug, true);
+  }
 };
diff --git a/test/unit/marked-spec.js b/test/unit/marked-spec.js
index 53b0d90818..c80868a832 100644
--- a/test/unit/marked-spec.js
+++ b/test/unit/marked-spec.js
@@ -63,6 +63,12 @@ describe('Test slugger functionality', () => {
     const slugger = new marked.Slugger();
     expect(slugger.slug('<em>html</em>')).toBe('html');
   });
+
+  it('should not increment seen when just getting text', () => {
+    const slugger = new marked.Slugger();
+    slugger.slugText('<h1>This Section</h1>');
+    expect(slugger.slug('<h1>This Section</h1>')).toBe('this-section');
+  });
 });
 
 describe('Test paragraph token type', () => {

From 2290f677c971c7e6bed2229fa8fef9ee5b340dcd Mon Sep 17 00:00:00 2001
From: flouc001 <flouc001@gmail.com>
Date: Sat, 11 Jul 2020 09:36:24 +0100
Subject: [PATCH 2/6] update docs

---
 docs/USING_PRO.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/docs/USING_PRO.md b/docs/USING_PRO.md
index 5912d2b5e6..418fd1e3ce 100644
--- a/docs/USING_PRO.md
+++ b/docs/USING_PRO.md
@@ -82,6 +82,16 @@ slugger.slug('foo-1') // foo-1-2
 ...
 ```
 
+`slugger` also has a stateless method `slugText` which does not update the internal accumulator:
+```js
+slugger.slug('foo')      // foo
+slugger.slugText('foo')  // foo-1
+slugger.slug('foo')      // foo-1
+slugger.slugText('foo')  // foo-2
+slugger.slug('foo')      // foo-2
+...
+```
+
 `flags` has the following properties:
 
 ```js

From 710658cb61b92061eb16d05e9e6c313f46de541a Mon Sep 17 00:00:00 2001
From: flouc001 <flouc001@gmail.com>
Date: Sun, 12 Jul 2020 19:38:37 +0100
Subject: [PATCH 3/6] use options param, update docs, update tests

---
 docs/USING_PRO.md        | 12 ++++++------
 src/Slugger.js           | 14 ++++----------
 test/unit/marked-spec.js | 10 ++++++++--
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/docs/USING_PRO.md b/docs/USING_PRO.md
index 418fd1e3ce..fb70f46d69 100644
--- a/docs/USING_PRO.md
+++ b/docs/USING_PRO.md
@@ -82,13 +82,13 @@ slugger.slug('foo-1') // foo-1-2
 ...
 ```
 
-`slugger` also has a stateless method `slugText` which does not update the internal accumulator:
+`slugger.slug` can also be called with the `dryrun` option for stateless operation:
 ```js
-slugger.slug('foo')      // foo
-slugger.slugText('foo')  // foo-1
-slugger.slug('foo')      // foo-1
-slugger.slugText('foo')  // foo-2
-slugger.slug('foo')      // foo-2
+slugger.slug('foo')                    // foo
+slugger.slug('foo', { dryrun: true })  // foo-1
+slugger.slug('foo')                    // foo-1
+slugger.slug('foo', { dryrun: true })  // foo-2
+slugger.slug('foo')                    // foo-2
 ...
 ```
 
diff --git a/src/Slugger.js b/src/Slugger.js
index 75e16c85a3..db385f54dd 100644
--- a/src/Slugger.js
+++ b/src/Slugger.js
@@ -39,17 +39,11 @@ module.exports = class Slugger {
 
   /**
    * Convert string to unique id
+   * @param {object} options
+   * @param {boolean} options.dryrun Generates the next unique slug without updating the internal accumulator.
    */
-  slug(value) {
+  slug(value, options = {}) {
     const slug = this.serialize(value);
-    return this.getNextSafeSlug(slug);
-  }
-
-  /**
-   * Get slug text without incrementing accumulator
-   */
-  slugText(value) {
-    const slug = this.serialize(value);
-    return this.getNextSafeSlug(slug, true);
+    return this.getNextSafeSlug(slug, options.dryrun);
   }
 };
diff --git a/test/unit/marked-spec.js b/test/unit/marked-spec.js
index c80868a832..93ce922e58 100644
--- a/test/unit/marked-spec.js
+++ b/test/unit/marked-spec.js
@@ -64,11 +64,17 @@ describe('Test slugger functionality', () => {
     expect(slugger.slug('<em>html</em>')).toBe('html');
   });
 
-  it('should not increment seen when just getting text', () => {
+  it('should not increment seen when using dryrun option', () => {
     const slugger = new marked.Slugger();
-    slugger.slugText('<h1>This Section</h1>');
+    slugger.slug('<h1>This Section</h1>', { dryrun: true });
     expect(slugger.slug('<h1>This Section</h1>')).toBe('this-section');
   });
+
+  it('should still return the next unique id when using dryrun', () => {
+    const slugger = new marked.Slugger();
+    expect(slugger.slug('<h1>This Section</h1>')).toBe('this-section');
+    expect(slugger.slug('<h1>This Section</h1>', { dryrun: true })).toBe('this-section-1');
+  });
 });
 
 describe('Test paragraph token type', () => {

From 0c415fd82e195bfadbcd910cdc3f8d539fd12e2a Mon Sep 17 00:00:00 2001
From: Callum <flouc001@gmail.com>
Date: Wed, 15 Jul 2020 08:02:55 +0100
Subject: [PATCH 4/6] update docs example to be clearer

Co-authored-by: Steven <steven@ceriously.com>
---
 docs/USING_PRO.md | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/docs/USING_PRO.md b/docs/USING_PRO.md
index fb70f46d69..ab684f662e 100644
--- a/docs/USING_PRO.md
+++ b/docs/USING_PRO.md
@@ -85,10 +85,12 @@ slugger.slug('foo-1') // foo-1-2
 `slugger.slug` can also be called with the `dryrun` option for stateless operation:
 ```js
 slugger.slug('foo')                    // foo
-slugger.slug('foo', { dryrun: true })  // foo-1
 slugger.slug('foo')                    // foo-1
-slugger.slug('foo', { dryrun: true })  // foo-2
 slugger.slug('foo')                    // foo-2
+slugger.slug('foo', { dryrun: true })  // foo-3
+slugger.slug('foo', { dryrun: true })  // foo-3
+slugger.slug('foo')                    // foo-3
+slugger.slug('foo')                    // foo-4
 ...
 ```
 

From 014fbcf43f7bd805b79757e0b10154be51f911bc Mon Sep 17 00:00:00 2001
From: Callum <flouc001@gmail.com>
Date: Wed, 15 Jul 2020 08:03:31 +0100
Subject: [PATCH 5/6] add assertion to existing test

Co-authored-by: Tony Brix <tony@brix.ninja>
---
 test/unit/marked-spec.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/unit/marked-spec.js b/test/unit/marked-spec.js
index 93ce922e58..2581a6d57f 100644
--- a/test/unit/marked-spec.js
+++ b/test/unit/marked-spec.js
@@ -66,7 +66,7 @@ describe('Test slugger functionality', () => {
 
   it('should not increment seen when using dryrun option', () => {
     const slugger = new marked.Slugger();
-    slugger.slug('<h1>This Section</h1>', { dryrun: true });
+    expect(slugger.slug('<h1>This Section</h1>', { dryrun: true })).toBe('this-section');
     expect(slugger.slug('<h1>This Section</h1>')).toBe('this-section');
   });
 

From 75b2646687d007b6bc18e40066a1395c1b26dd03 Mon Sep 17 00:00:00 2001
From: flouc001 <flouc001@gmail.com>
Date: Wed, 15 Jul 2020 08:16:03 +0100
Subject: [PATCH 6/6] add sequence test

---
 test/unit/marked-spec.js | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/test/unit/marked-spec.js b/test/unit/marked-spec.js
index 2581a6d57f..2f88258133 100644
--- a/test/unit/marked-spec.js
+++ b/test/unit/marked-spec.js
@@ -75,6 +75,17 @@ describe('Test slugger functionality', () => {
     expect(slugger.slug('<h1>This Section</h1>')).toBe('this-section');
     expect(slugger.slug('<h1>This Section</h1>', { dryrun: true })).toBe('this-section-1');
   });
+
+  it('should be repeatable in a sequence', () => {
+    const slugger = new marked.Slugger();
+    expect(slugger.slug('foo')).toBe('foo');
+    expect(slugger.slug('foo')).toBe('foo-1');
+    expect(slugger.slug('foo')).toBe('foo-2');
+    expect(slugger.slug('foo', { dryrun: true })).toBe('foo-3');
+    expect(slugger.slug('foo', { dryrun: true })).toBe('foo-3');
+    expect(slugger.slug('foo')).toBe('foo-3');
+    expect(slugger.slug('foo')).toBe('foo-4');
+  });
 });
 
 describe('Test paragraph token type', () => {