Enforce new code must have not errors or warns

Travis Ci will run the linter on any modifed js or php files. If
there are errors or warnings, then lint will be run on the previous
version of the file (if there was one). If new errors or warning have been introduced then
the build is in error.

.travis.build.sh

@@ -32,7 +32,7 @@ if [ "$TEST_SUITE" = "syntax" ] || [ "$TEST_SUITE" = "style" ]; then
     files_changed=()
     while IFS= read -r -d $'\0' file; do
         files_changed+=("$file")
-    done < <(git diff --name-only --diff-filter=d -z "$TRAVIS_COMMIT_RANGE")
+    done < <(git diff --name-only --diff-filter=da -z "$TRAVIS_COMMIT_RANGE")
 
     # Separate the changed files by language.
     php_files_changed=()
@@ -44,6 +44,17 @@ if [ "$TEST_SUITE" = "syntax" ] || [ "$TEST_SUITE" = "style" ]; then
             js_files_changed+=("$file")
         fi
     done
+
+    # Get any added files by language
+    php_files_added=()
+    js_files_added=()
+    while IFS= read -r -d $'\0' file; do
+        if [[ "$file" == *.php ]]; then
+            php_files_added+=("$file")
+        elif [[ "$file" == *.js ]]; then
+            js_files_added+=("$file")
+        fi
+    done < <(git diff --name-only --diff-filter=A -z "$TRAVIS_COMMIT_RANGE")
 fi
 
 # Perform a test set based on the value of $TEST_SUITE.
@@ -62,13 +73,39 @@ if [ "$TEST_SUITE" = "syntax" ]; then
         fi
     done
 elif [ "$TEST_SUITE" = "style" ]; then
+    npm install https://github.com/jpwhite4/lint-diff/tarball/master
+
     for file in "${php_files_changed[@]}"; do
+        phpcs "$file" --report=json > "$file.lint.new.json"
+        if [ $? != 0 ]; then
+            git show "$commit_range_start:$file" | phpcs --stdin-path="$file" --report=json > "$file.lint.orig.json"
+            ./node_modules/.bin/lint-diff "$file.lint.orig.json" "$file.lint.new.json"
+            if [ $? != 0 ]; then
+                build_exit_value=2
+            fi
+            rm "$file.lint.orig.json"
+        fi
+        rm "$file.lint.new.json"
+    done
+    for file in "${php_files_added[@]}"; do
         phpcs "$file"
         if [ $? != 0 ]; then
             build_exit_value=2
         fi
     done
     for file in "${js_files_changed[@]}"; do
+        eslint "$file" -f json > "$file.lint.new.json"
+        if [ $? != 0 ]; then
+            git show "$commit_range_start:$file" | eslint --stdin --stdin-filename "$file" -f json > "$file.lint.orig.json"
+            ./node_modules/.bin/lint-diff "$file.lint.orig.json" "$file.lint.new.json"
+            if [ $? != 0 ]; then
+                build_exit_value=2
+            fi
+            rm "$file.lint.orig.json"
+        fi
+        rm "$file.lint.new.json"
+    done
+    for file in "${js_files_added[@]}"; do
         eslint "$file"
         if [ $? != 0 ]; then
             build_exit_value=2

.travis.yml

@@ -15,10 +15,6 @@ env:
         - TEST_SUITE=unit
         - TEST_SUITE=build
 
-matrix:
-    allow_failures:
-        - env: TEST_SUITE=style
-
 # Add dependency directories to the Travis cache
 cache:
     directories: