Merge pull request #10 from gruntwork-io/feature/file-fill-template

Add function to fill out template strings in files

Author: tonerdo

modules/bash-commons/src/file.sh

@@ -4,6 +4,7 @@
 set -e
 
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/os.sh"
+source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/string.sh"
 
 # Returns true (0) if the given file exists and is a file and false (1) otherwise
 function file_exists {
@@ -63,3 +64,23 @@ function file_replace_or_append_text {
     file_append_text "$replacement_text" "$file"
   fi
 }
+
+# Replace a specific template string in a file with a value. Provided as an array of TEMPLATE-STRING=VALUE
+function file_fill_template {
+  local -r file="$1"
+  shift 1
+  local -ar auto_fill=("$@")
+
+  if [[ -z "${auto_fill[@]}" ]]; then
+    log_info "No auto-fill params specified."
+    return
+  fi
+
+  local name
+  local value
+  for param in "${auto_fill[@]}"; do
+    name="$(string_strip_suffix "$param" "=*")"
+    value="$(string_strip_prefix "$param" "*=")"
+    file_replace_text "$name" "$value" "$file"
+  done
+}

test/file.bats

@@ -203,4 +203,57 @@ load "test-helper"
   assert_equal "$expected" "$actual"
 
   rm -f "$tmp_file"
-}
+}
+
+@test "file_fill_template non empty file, nothing to replace" {
+  local -r tmp_file=$(mktemp)
+  local -ar auto_fill=("<__PLACEHOLDER__>=hello")
+  local -r file_contents=$(echo -e "abc\nhey world\nbaz")
+
+  echo "$file_contents" > "$tmp_file"
+
+  run file_fill_template "$tmp_file" "${auto_fill[@]}"
+  assert_success
+
+  local -r actual=$(cat "$tmp_file")
+  local -r expected=$file_contents
+  assert_equal "$expected" "$actual"
+
+  rm -f "$tmp_file"
+}
+
+@test "file_fill_template non empty file, replace text" {
+  local -r tmp_file=$(mktemp)
+  local -ar auto_fill=("<__PLACEHOLDER__>=hello")
+  local -r file_contents=$(echo -e "abc\n<__PLACEHOLDER__> world\nbaz")
+
+  echo "$file_contents" > "$tmp_file"
+
+  run file_fill_template "$tmp_file" "${auto_fill[@]}"
+  assert_success
+
+  local -r actual=$(cat "$tmp_file")
+  local -r expected=$(echo -e "abc\nhello world\nbaz")
+  assert_equal "$expected" "$actual"
+
+  rm -f "$tmp_file"
+}
+
+@test "file_fill_template non empty file, replace multiple" {
+  local -r tmp_file=$(mktemp)
+  local -a auto_fill=("<__PLACEHOLDER__>=hello")
+  auto_fill+=("<__PLACEHOLDER2__>=foo")
+
+  local -r file_contents=$(echo -e "abc\n<__PLACEHOLDER__> world\n<__PLACEHOLDER2__> baz")
+
+  echo "$file_contents" > "$tmp_file"
+
+  run file_fill_template "$tmp_file" "${auto_fill[@]}"
+  assert_success
+
+  local -r actual=$(cat "$tmp_file")
+  local -r expected=$(echo -e "abc\nhello world\nfoo baz")
+  assert_equal "$expected" "$actual"
+
+  rm -f "$tmp_file"
+}