feat(tools): add fs_patch.sh (#124)

3 files changed, 155 insertions, 4 deletions

diff --git a/tools/fs_patch.sh b/tools/fs_patch.sh
new file mode 100755
index 0000000..14e46d2
--- /dev/null
+++ b/tools/fs_patch.sh
@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+set -e
+
+# @describe Apply a patch to a file at the specified path.
+# This can be used to edit the file, without having to rewrite the whole file.
+
+# @option --path! The path of the file to apply to
+# @option --contents! The patch to apply to the file
+#
+# Here is an example of a patch block that can be applied to modify the file to request the user's name:
+# --- a/hello.py
+# +++ b/hello.py
+# \@@ ... @@
+#  def hello():
+# -    print("Hello World")
+# +    name = input("What is your name? ")
+# +    print(f"Hello {name}")
+
+# @env LLM_OUTPUT=/dev/stdout The output path
+
+main() {
+    if [ ! -f "$argc_path" ]; then
+        echo "Not found file: $argc_path"
+        exit 1
+    fi
+    root_dir="${LLM_ROOT_DIR:-$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)}"
+    new_contents="$(awk -f "$root_dir/utils/patch.awk" "$argc_path" <(printf "%s" "$argc_contents"))"
+    printf "%s" "$new_contents" | git diff --no-index "$argc_path" - || true
+    if [ -t 1 ]; then
+        echo
+        read -r -p "Apply changes? [Y/n] " ans
+        if [[ "$ans" == "N" || "$ans" == "n" ]]; then
+            echo "Aborted!"
+            exit 1
+        fi
+    fi
+    printf "%s" "$new_contents" > "$argc_path"
+
+    echo "The patch applied to: $argc_path" >> "$LLM_OUTPUT"
+}
+
+eval "$(argc --argc-eval "$0" "$@")"
diff --git a/tools/fs_write.sh b/tools/fs_write.sh
index bdf8e85..0e0dba0 100755
--- a/tools/fs_write.sh
+++ b/tools/fs_write.sh
@@ -1,10 +1,7 @@
 #!/usr/bin/env bash
 set -e
 
-# @describe Write the contents to a file at the specified path.
-# If the file exists, only the necessary changes will be applied.
-# If the file doesn't exist, it will be created.
-# Always provide the full intended contents of the file.
+# @describe Write the full file contents to a file at the specified path.
 
 # @option --path! The path of the file to write to
 # @option --contents! The full contents to write to the file
diff --git a/utils/patch.awk b/utils/patch.awk
new file mode 100755
index 0000000..b625d37
--- /dev/null
+++ b/utils/patch.awk
@@ -0,0 +1,112 @@
+#!/usr/bin/awk -f
+
+# Apply a diff file to an original
+# Usage: awk -f patch.awk target-file patch-file
+
+FNR == NR {
+    lines[FNR] = $0
+    next;
+}
+
+{
+    patchLines[FNR] = $0
+}
+
+END {
+    totalPatchLines=length(patchLines)
+    totalLines = length(lines)
+    patchLineIndex = 1
+
+    mode = "none"
+
+    while (patchLineIndex <= totalPatchLines) {
+        line = patchLines[patchLineIndex]
+
+        if (line ~ /^--- / || line ~ /^\+\+\+ /) {
+            patchLineIndex++
+            continue
+        }
+
+        if (line ~ /^@@ /) {
+            mode = "hunk"
+            hunkIndex++
+            patchLineIndex++
+            continue
+        }
+
+        if (mode == "hunk") {
+            while (patchLineIndex <= totalPatchLines && line ~ /^[-+ ]/ && line !~ /^--- /) {
+                sanitizedLine = substr(line, 2)
+                if (line !~ /^\+/) {
+                    hunkTotalOriginalLines[hunkIndex]++;
+                    hunkOriginalLines[hunkIndex,hunkTotalOriginalLines[hunkIndex]] = sanitizedLine
+                } 
+                if (line !~ /^-/) {
+                    hunkTotalUpdatedLines[hunkIndex]++;
+                    hunkUpdatedLines[hunkIndex,hunkTotalUpdatedLines[hunkIndex]] = sanitizedLine
+                }
+                patchLineIndex++
+                line = patchLines[patchLineIndex]
+            }
+            mode = "none"
+        } else {
+            patchLineIndex++
+        }
+    }
+
+    if (hunkIndex == 0) {
+        print "No patch" > "/dev/stderr"
+        exit 1
+    }
+
+    totalHunks = hunkIndex
+    hunkIndex = 1
+
+    # inspectHunks()
+
+    for (lineIndex = 1; lineIndex <= totalLines; lineIndex++) {
+        line = lines[lineIndex]
+        nextLineIndex = 0
+
+        if (line == hunkOriginalLines[hunkIndex,1]) {
+            nextLineIndex = lineIndex + 1
+            for (i = 2; i <= hunkTotalOriginalLines[hunkIndex]; i++) {
+                if (lines[nextLineIndex] != hunkOriginalLines[hunkIndex,i]) {
+                    nextLineIndex = 0
+                    break
+                }
+                nextLineIndex++
+            }
+        }
+        if (nextLineIndex > 0) {
+            for (i = 1; i <= hunkTotalUpdatedLines[hunkIndex]; i++) {
+                print hunkUpdatedLines[hunkIndex,i]
+            }
+            hunkIndex++
+            lineIndex = nextLineIndex -1;
+        } else {
+            print line
+        }
+    }
+
+    if (hunkIndex != totalHunks + 1) {
+        print "Failed to patch the file" > "/dev/stderr"
+        exit 1
+    }
+}
+
+function inspectHunks() {
+    print "/* Begin inspecting hunks"
+    for (i = 1; i <= totalHunks; i++) {
+        print ">>>>>> Original"
+        for (j = 1; j <= hunkTotalOriginalLines[i]; j++) {
+            print hunkOriginalLines[i,j]
+        }
+        print "======"
+        for (j = 1; j <= hunkTotalUpdatedLines[i]; j++) {
+            print hunkUpdatedLines[i,j]
+        }
+        print "<<<<<< Updated"
+    }
+    print "End inspecting hunks */\n"
+}
\ No newline at end of file