From 7484adc70dca7e0c1a073e4cea755c2607930f15 Mon Sep 17 00:00:00 2001
From: Sean <seantdwilson@gmail.com>
Date: Fri, 8 Sep 2017 12:54:02 -0700
Subject: [PATCH 1/4] Add tests for expected behaviour

---
 test/getMetaInfo.spec.js | 60 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/test/getMetaInfo.spec.js b/test/getMetaInfo.spec.js
index 35572a8..54512b3 100644
--- a/test/getMetaInfo.spec.js
+++ b/test/getMetaInfo.spec.js
@@ -69,4 +69,64 @@ describe('getMetaInfo', () => {
       __dangerouslyDisableSanitizers: []
     })
   })
+
+  it('properly uses string titleTemplates', () => {
+    component = new Vue({
+      metaInfo: {
+        title: 'Hello',
+        titleTemplate: '%s World',
+        meta: [
+          { charset: 'utf-8' }
+        ]
+      }
+    })
+    expect(getMetaInfo(component)).to.eql({
+      title: 'Hello World',
+      titleChunk: 'Hello',
+      titleTemplate: '%s World',
+      htmlAttrs: {},
+      headAttrs: {},
+      bodyAttrs: {},
+      meta: [
+        { charset: 'utf-8' }
+      ],
+      base: [],
+      link: [],
+      style: [],
+      script: [],
+      noscript: [],
+      __dangerouslyDisableSanitizers: []
+    })
+  })
+
+  it('properly uses function titleTemplates', () => {
+    const titleTemplate = chunk => `${chunk} Function World`
+
+    component = new Vue({
+      metaInfo: {
+        title: 'Hello',
+        titleTemplate: titleTemplate,
+        meta: [
+          { charset: 'utf-8' }
+        ]
+      }
+    })
+    expect(getMetaInfo(component)).to.eql({
+      title: 'Hello Function World',
+      titleChunk: 'Hello',
+      titleTemplate: titleTemplate,
+      htmlAttrs: {},
+      headAttrs: {},
+      bodyAttrs: {},
+      meta: [
+        { charset: 'utf-8' }
+      ],
+      base: [],
+      link: [],
+      style: [],
+      script: [],
+      noscript: [],
+      __dangerouslyDisableSanitizers: []
+    })
+  })
 })

From c3cc4bdae4132770e6bf42b730e38508a694df3e Mon Sep 17 00:00:00 2001
From: Sean <seantdwilson@gmail.com>
Date: Fri, 8 Sep 2017 12:54:09 -0700
Subject: [PATCH 2/4] Allow titleTemplate to be a function

---
 src/shared/getMetaInfo.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/shared/getMetaInfo.js b/src/shared/getMetaInfo.js
index 284b703..db37a76 100644
--- a/src/shared/getMetaInfo.js
+++ b/src/shared/getMetaInfo.js
@@ -84,7 +84,11 @@ export default function _getMetaInfo (options = {}) {
 
     // replace title with populated template
     if (info.titleTemplate) {
-      info.title = info.titleTemplate.replace(/%s/g, info.titleChunk)
+      if (typeof info.titleTemplate === 'function') {
+        info.title = info.titleTemplate(info.titleChunk)
+      } else {
+        info.title = info.titleTemplate.replace(/%s/g, info.titleChunk)
+      }
     }
 
     // convert base tag to an array so it can be handled the same way

From 47fb79e0ee539f82bbc51f4c72829d30fdc980f4 Mon Sep 17 00:00:00 2001
From: Sean <seantdwilson@gmail.com>
Date: Fri, 8 Sep 2017 12:58:59 -0700
Subject: [PATCH 3/4] Add test to check `this` binding during function call

---
 test/getMetaInfo.spec.js | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/test/getMetaInfo.spec.js b/test/getMetaInfo.spec.js
index 54512b3..c69a644 100644
--- a/test/getMetaInfo.spec.js
+++ b/test/getMetaInfo.spec.js
@@ -129,4 +129,42 @@ describe('getMetaInfo', () => {
       __dangerouslyDisableSanitizers: []
     })
   })
+
+  it('has the proper `this` binding when using function titleTemplates', () => {
+    const titleTemplate = function (chunk) {
+      return `${chunk} ${this.helloWorldText}`
+    }
+
+    component = new Vue({
+      metaInfo: {
+        title: 'Hello',
+        titleTemplate: titleTemplate,
+        meta: [
+          { charset: 'utf-8' }
+        ]
+      },
+      data () {
+        return {
+          helloWorldText: 'Function World'
+        }
+      }
+    })
+    expect(getMetaInfo(component)).to.eql({
+      title: 'Hello Function World',
+      titleChunk: 'Hello',
+      titleTemplate: titleTemplate,
+      htmlAttrs: {},
+      headAttrs: {},
+      bodyAttrs: {},
+      meta: [
+        { charset: 'utf-8' }
+      ],
+      base: [],
+      link: [],
+      style: [],
+      script: [],
+      noscript: [],
+      __dangerouslyDisableSanitizers: []
+    })
+  })
 })

From 6283e1e3fd072c80c2409c6e9049d07ae373a0fe Mon Sep 17 00:00:00 2001
From: Sean <seantdwilson@gmail.com>
Date: Fri, 8 Sep 2017 12:59:10 -0700
Subject: [PATCH 4/4] Bind titleTemplate function call to component instance

---
 src/shared/getMetaInfo.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/shared/getMetaInfo.js b/src/shared/getMetaInfo.js
index db37a76..92613b0 100644
--- a/src/shared/getMetaInfo.js
+++ b/src/shared/getMetaInfo.js
@@ -85,7 +85,7 @@ export default function _getMetaInfo (options = {}) {
     // replace title with populated template
     if (info.titleTemplate) {
       if (typeof info.titleTemplate === 'function') {
-        info.title = info.titleTemplate(info.titleChunk)
+        info.title = info.titleTemplate.call(component, info.titleChunk)
       } else {
         info.title = info.titleTemplate.replace(/%s/g, info.titleChunk)
       }