Feature: Add append to array

Adds the ability to append a value to an array instead of having to
know the index of the values within the array.

Resolves: #17

commands_test.go

@@ -435,6 +435,25 @@ func TestWriteCmd_Inplace(t *testing.T) {
 	assertResult(t, expectedOutput, gotOutput)
 }
 
+func TestWriteCmd_Append(t *testing.T) {
+	content := `b:
+  - foo
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("write %s b[+] 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+- foo
+- 7
+`
+	assertResult(t, expectedOutput, result.Output)
+}
+
 func TestMergeCmd(t *testing.T) {
 	cmd := getRootCommand()
 	result := runCmd(cmd, "merge examples/data1.yaml examples/data2.yaml")

data_navigator.go

@@ -55,7 +55,7 @@ func updatedChildValue(child interface{}, remainingPaths []string, value interfa
 	}
 
 	_, nextIndexErr := strconv.ParseInt(remainingPaths[0], 10, 64)
-	if nextIndexErr != nil {
+	if nextIndexErr != nil && remainingPaths[0] != "+" {
 		// must be a map
 		return writeMap(child, remainingPaths, value)
 	}
@@ -81,7 +81,13 @@ func writeArray(context interface{}, paths []string, value interface{}) []interf
 	log.Debugf("\tarray %v\n", array)
 
 	rawIndex := paths[0]
-	index, _ := strconv.ParseInt(rawIndex, 10, 64)
+	var index int64
+	// the append array indicator
+	if rawIndex == "+" {
+		index = int64(len(array))
+	} else {
+		index, _ = strconv.ParseInt(rawIndex, 10, 64)
+	}
 	// writeArray is only called by updatedChildValue which handles parsing the
 	// index, as such this renders this dead code.
 	// if err != nil {

docs/mkdocs/search_index.json

@@ -57,7 +57,7 @@
         }, 
         {
             "location": "/write/", 
-            "text": "yaml w \nyaml_file|json_file\n \npath\n \nnew value\n\n\n\n\n\nThis command can take a json file as input too, and will output yaml unless specified to export as json (-j)\n\n\nTo Stdout\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.c cat\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n\n\n\n\nFrom STDIN\n\n\ncat sample.yaml | yaml w - b.c blah\n\n\n\n\nAdding new fields\n\n\nAny missing fields in the path will be created on the fly.\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.d[0] \nnew thing\n\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n  d:\n    - new thing\n\n\n\n\nUpdating files in-place\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w -i sample.yaml b.c cat\n\n\n\n\nwill update the sample.yaml file so that the value of 'c' is cat.\n\n\nUpdating multiple values with a script\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n  e:\n    - name: Billy Bob\n\n\n\n\nand a script update_instructions.yaml of:\n\n\nb.c: 3\nb.e[0].name: Howdy Partner\n\n\n\n\nthen\n\n\nyaml w -s update_instructions.yaml sample.yaml\n\n\n\n\nwill output:\n\n\nb:\n  c: 3\n  e:\n    - name: Howdy Partner\n\n\n\n\nAnd, of course, you can pipe the instructions in using '-':\n\n\ncat update_instructions.yaml | yaml w -s - sample.yaml\n\n\n\n\nValues starting with a hyphen (or dash)\n\n\nThe flag terminator needs to be used to stop the app from attempting to parse the subsequent arguments as flags:\n\n\nyaml w -- my.path -3\n\n\n\n\nwill output\n\n\nmy:\n  path: -3", 
+            "text": "yaml w \nyaml_file|json_file\n \npath\n \nnew value\n\n\n\n\n\nThis command can take a json file as input too, and will output yaml unless specified to export as json (-j)\n\n\nTo Stdout\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.c cat\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n\n\n\n\nFrom STDIN\n\n\ncat sample.yaml | yaml w - b.c blah\n\n\n\n\nAdding new fields\n\n\nAny missing fields in the path will be created on the fly.\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.d[0] \nnew thing\n\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n  d:\n    - new thing\n\n\n\n\nAppending value to an array field\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n  d:\n    - new thing\n    - foo thing\n\n\n\n\nthen\n\n\nyaml w sample.yaml b.d[+] \nbar thing\n\n\n\n\n\nwill output:\n\n\nb:\n  c: cat\n  d:\n    - new thing\n    - foo thing\n    - bar thing\n\n\n\n\nUpdating files in-place\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n\n\n\n\nthen\n\n\nyaml w -i sample.yaml b.c cat\n\n\n\n\nwill update the sample.yaml file so that the value of 'c' is cat.\n\n\nUpdating multiple values with a script\n\n\nGiven a sample.yaml file of:\n\n\nb:\n  c: 2\n  e:\n    - name: Billy Bob\n\n\n\n\nand a script update_instructions.yaml of:\n\n\nb.c: 3\nb.e[0].name: Howdy Partner\n\n\n\n\nthen\n\n\nyaml w -s update_instructions.yaml sample.yaml\n\n\n\n\nwill output:\n\n\nb:\n  c: 3\n  e:\n    - name: Howdy Partner\n\n\n\n\nAnd, of course, you can pipe the instructions in using '-':\n\n\ncat update_instructions.yaml | yaml w -s - sample.yaml\n\n\n\n\nValues starting with a hyphen (or dash)\n\n\nThe flag terminator needs to be used to stop the app from attempting to parse the subsequent arguments as flags:\n\n\nyaml w -- my.path -3\n\n\n\n\nwill output\n\n\nmy:\n  path: -3", 
             "title": "Write/Update"
         }, 
         {
@@ -75,6 +75,11 @@
             "text": "Any missing fields in the path will be created on the fly.  Given a sample.yaml file of:  b:\n  c: 2  then  yaml w sample.yaml b.d[0]  new thing   will output:  b:\n  c: cat\n  d:\n    - new thing", 
             "title": "Adding new fields"
         }, 
+        {
+            "location": "/write/#appending-value-to-an-array-field", 
+            "text": "Given a sample.yaml file of:  b:\n  c: 2\n  d:\n    - new thing\n    - foo thing  then  yaml w sample.yaml b.d[+]  bar thing   will output:  b:\n  c: cat\n  d:\n    - new thing\n    - foo thing\n    - bar thing", 
+            "title": "Appending value to an array field"
+        }, 
         {
             "location": "/write/#updating-files-in-place", 
             "text": "Given a sample.yaml file of:  b:\n  c: 2  then  yaml w -i sample.yaml b.c cat  will update the sample.yaml file so that the value of 'c' is cat.", 

docs/sitemap.xml

@@ -4,7 +4,7 @@
     
     <url>
      <loc>/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -12,7 +12,7 @@
     
     <url>
      <loc>/read/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -20,7 +20,7 @@
     
     <url>
      <loc>/write/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -28,7 +28,7 @@
     
     <url>
      <loc>/create/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -36,7 +36,7 @@
     
     <url>
      <loc>/convert/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     
@@ -44,7 +44,7 @@
     
     <url>
      <loc>/merge/</loc>
-     <lastmod>2017-09-23</lastmod>
+     <lastmod>2017-09-24</lastmod>
      <changefreq>daily</changefreq>
     </url>
     

docs/write/index.html

@@ -250,6 +250,13 @@
     Adding new fields
   </a>
   
+</li>
+      
+        <li class="md-nav__item">
+  <a href="#appending-value-to-an-array-field" title="Appending value to an array field" class="md-nav__link">
+    Appending value to an array field
+  </a>
+  
 </li>
       
         <li class="md-nav__item">
@@ -355,6 +362,13 @@
     Adding new fields
   </a>
   
+</li>
+      
+        <li class="md-nav__item">
+  <a href="#appending-value-to-an-array-field" title="Appending value to an array field" class="md-nav__link">
+    Appending value to an array field
+  </a>
+  
 </li>
       
         <li class="md-nav__item">
@@ -436,6 +450,28 @@
     - new thing
 </code></pre>
 
+<h3 id="appending-value-to-an-array-field">Appending value to an array field<a class="headerlink" href="#appending-value-to-an-array-field" title="Permanent link">&para;</a></h3>
+<p>Given a sample.yaml file of:</p>
+<pre><code class="yaml">b:
+  c: 2
+  d:
+    - new thing
+    - foo thing
+</code></pre>
+
+<p>then</p>
+<pre><code class="bash">yaml w sample.yaml b.d[+] &quot;bar thing&quot;
+</code></pre>
+
+<p>will output:</p>
+<pre><code class="yaml">b:
+  c: cat
+  d:
+    - new thing
+    - foo thing
+    - bar thing
+</code></pre>
+
 <h3 id="updating-files-in-place">Updating files in-place<a class="headerlink" href="#updating-files-in-place" title="Permanent link">&para;</a></h3>
 <p>Given a sample.yaml file of:</p>
 <pre><code class="yaml">b:

mkdocs/write.md

@@ -44,6 +44,29 @@ b:
     - new thing
 ```
 
+### Appending value to an array field
+Given a sample.yaml file of:
+```yaml
+b:
+  c: 2
+  d:
+    - new thing
+    - foo thing
+```
+then
+```bash
+yaml w sample.yaml b.d[+] "bar thing"
+```
+will output:
+```yaml
+b:
+  c: cat
+  d:
+    - new thing
+    - foo thing
+    - bar thing
+```
+
 ### Updating files in-place
 Given a sample.yaml file of:
 ```yaml

path_parser_test.go

@@ -10,6 +10,7 @@ var parsePathsTests = []struct {
 }{
 	{"a.b", []string{"a", "b"}},
 	{"a.b[0]", []string{"a", "b", "0"}},
+	{"a.b.d[+]", []string{"a", "b", "d", "+"}},
 }
 
 func TestParsePath(t *testing.T) {

yaml.go

@@ -98,10 +98,14 @@ yaml write --inplace things.yaml a.b.c cat
 yaml w -i things.yaml a.b.c cat
 yaml w --script update_script.yaml things.yaml
 yaml w -i -s update_script.yaml things.yaml
+yaml w things.yaml a.b.d[+] foo
+yaml w things.yaml a.b.d[+] foo
       `,
 		Long: `Updates the yaml file w.r.t the given path and value.
 Outputs to STDOUT unless the inplace flag is used, in which case the file is updated instead.
 
+Append value to array adds the value to the end of array.
+
 Update Scripts:
 Note that you can give an update script to perform more sophisticated updated. Update script
 format is a yaml map where the key is the path and the value is..well the value. e.g.: