From c0eaaac6200d38f56a090614da7aa85a98cd8a3f Mon Sep 17 00:00:00 2001
From: Oleg Tarasov <oleg.v.tarasov@gmail.com>
Date: Fri, 28 Feb 2020 15:07:28 +0300
Subject: [PATCH] Added regex params, renamed env var

---
 README.md   | 18 +++++++++++++-----
 action.yml  |  2 +-
 lib/main.js | 17 +++++++++++++++--
 src/main.ts | 17 +++++++++++++++--
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index c21e767c..dfea9719 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,8 @@
 # Get tag name
 
-This simple action gets tag name from commit that triggered the action and puts it into an environment variable GITHUB_TAG_NAME.  It will also export is as an output
-named "tag".
+This action gets tag name from commit that triggered the action and puts it into an environment variable GIT_TAG_NAME.  It will also export is as an output named "tag".
+
+You can also use optional parameters `tagRegex` and `tagRegexGroup` to extract a part from tag string.
 
 ## Usage
 
@@ -9,9 +10,16 @@ Dead simple:
 
 ```yaml
     steps:
-      - uses: olegtarasov/get-tag@v1
+      - uses: olegtarasov/get-tag@v2
         id: tagName
-      - name: Some other step
         with:
-            tagname: ${{ steps.tagName.outputs.tag }}
+          tagRegex: "foobar-(.*)"  # Optional. Returns specified group text as tag name. Full tag string is returned if regex is not defined.
+          tagRegexGroup: 1 # Optional. Default is 1.
+      - name: Some other step # Output usage example
+        with:
+          tagname: ${{ steps.tagName.outputs.tag }}
+      - name: Yet another step # Environment variabl usage example
+        run: |
+          docker build . --file Dockerfile --tag docker.pkg.github.com/someimage:$GIT_TAG_NAME
+
 ```
diff --git a/action.yml b/action.yml
index 2b18cef5..805bf720 100644
--- a/action.yml
+++ b/action.yml
@@ -1,5 +1,5 @@
 name: 'Get tag name'
-description: 'Gets current tag name and puts it into an environment variable GITHUB_TAG_NAME.'
+description: 'Gets current tag name and puts it into an environment variable GIT_TAG_NAME.'
 author: 'Oleg Tarasov'
 runs:
   using: 'node12'
diff --git a/lib/main.js b/lib/main.js
index 6060d060..cdd93c1a 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -23,8 +23,21 @@ function run() {
             const ref = github.context.ref;
             const tagPath = "refs/tags/";
             if (ref && ref.startsWith(tagPath)) {
-                const tag = ref.substr(tagPath.length, ref.length);
-                core.exportVariable("GITHUB_TAG_NAME", tag);
+                var tag = ref.substr(tagPath.length, ref.length);
+                const regexStr = core.getInput("tagRegex");
+                if (regexStr) {
+                    const regex = new RegExp(regexStr);
+                    const groupIdx = parseInt(core.getInput("tagRegexGroup") || "1");
+                    const result = regex.exec(tag);
+                    if (result && result.length > groupIdx) {
+                        tag = result[groupIdx];
+                    }
+                    else {
+                        core.warning(`Failed to match regex '${regexStr}' in tag string '${tag}'. Result is '${result}'`);
+                        return;
+                    }
+                }
+                core.exportVariable("GIT_TAG_NAME", tag);
                 core.setOutput('tag', tag);
             }
         }
diff --git a/src/main.ts b/src/main.ts
index 435eefc1..d90602cd 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -6,8 +6,21 @@ async function run() {
     const ref = github.context.ref
     const tagPath = "refs/tags/"
     if (ref && ref.startsWith(tagPath)) {
-      const tag = ref.substr(tagPath.length, ref.length);
-      core.exportVariable("GITHUB_TAG_NAME", tag);
+      var tag = ref.substr(tagPath.length, ref.length);
+      const regexStr = core.getInput("tagRegex")
+      if (regexStr) {
+        const regex = new RegExp(regexStr)
+        const groupIdx = parseInt(core.getInput("tagRegexGroup") || "1")
+        const result = regex.exec(tag);
+        if (result && result.length > groupIdx) {
+          tag = result[groupIdx]
+        }
+        else {
+          core.warning(`Failed to match regex '${regexStr}' in tag string '${tag}'. Result is '${result}'`)
+          return
+        }
+      }
+      core.exportVariable("GIT_TAG_NAME", tag);
       core.setOutput('tag', tag);
     }
   } catch (error) {