diff --git a/src/lib/notcurses.c b/src/lib/notcurses.c
index 18793d025..c20783ce6 100644
--- a/src/lib/notcurses.c
+++ b/src/lib/notcurses.c
@@ -2138,6 +2138,9 @@ int ncplane_erase_region(ncplane* n, int ystart, int xstart, int ylen, int xlen)
     return -1;
   }
   if(xlen < 0){
+    if(xlen + 1 < -xstart){
+      xlen = -xstart - 1;
+    }
     xstart = xstart + xlen + 1;
     xlen = -xlen;
   }else if(xlen == 0){
@@ -2148,6 +2151,9 @@ int ncplane_erase_region(ncplane* n, int ystart, int xstart, int ylen, int xlen)
     xlen = ncplane_dim_x(n) - xstart;
   }
   if(ylen < 0){
+    if(ylen + 1 < -ystart){
+      ylen = -ystart - 1;
+    }
     ystart = ystart + ylen + 1;
     ylen = -ylen;
   }else if(ylen == 0){
diff --git a/src/tests/erase.cpp b/src/tests/erase.cpp
index 21cd502a4..86e726012 100644
--- a/src/tests/erase.cpp
+++ b/src/tests/erase.cpp
@@ -7,25 +7,171 @@ TEST_CASE("Erase") {
   if(!nc_){
     return;
   }
-  struct ncplane* n_ = notcurses_stdplane(nc_);
+  int dimy, dimx;
+  struct ncplane* n_ = notcurses_stddim_yx(nc_, &dimy, &dimx);
   REQUIRE(n_);
 
+  // fill the standard plane with 'x's
+  nccell nc = CELL_CHAR_INITIALIZER('x');
+  CHECK(0 < ncplane_polyfill_yx(n_, 0, 0, &nc));
+  nccell_release(n_, &nc);
+  CHECK(0 == notcurses_render(nc_));
+  CHECK(0 == ncplane_cursor_move_yx(n_, dimy / 2, dimx / 2));
+
   // clear all columns to the left of cursor, inclusive
   SUBCASE("EraseColumnsLeft") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, 0, -INT_MAX));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(x <= dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
   }
 
   // clear all columns to the right of cursor, inclusive
   SUBCASE("EraseColumnsRight") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, 0, INT_MAX));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(x >= dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
   }
 
   // clear all rows above cursor, inclusive
-  SUBCASE("EraseRowsLeft") {
+  SUBCASE("EraseRowsAbove") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, -INT_MAX, 0));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y <= dimy / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
   }
 
   // clear all rows below cursor, inclusive
   SUBCASE("EraseRowsBelow") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, INT_MAX, 0));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y >= dimy / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
+  }
+
+  // current cursor to the end of the line
+  SUBCASE("EraseToEOL") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, 1, INT_MAX));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y == dimy / 2 && x >= dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
+  }
+
+  // current cursor to the start of the line
+  SUBCASE("EraseToSOL") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, 1, -INT_MAX));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y == dimy / 2 && x <= dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
+  }
+
+  // current cursor to the end of the line using -1 len
+  SUBCASE("EraseToEOLNeg") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, -1, INT_MAX));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y == dimy / 2 && x >= dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
+  }
+
+  // current cursor to the start of the line using -1 len
+  SUBCASE("EraseToSOLNeg") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, -1, -INT_MAX));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y == dimy / 2 && x <= dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
+  }
+
+  // current cursor only
+  SUBCASE("EraseCurrentCursor") {
+    CHECK(0 == ncplane_erase_region(n_, -1, -1, 1, 1));
+    for(int y = 0 ; y < dimy ; ++y){
+      for(int x = 0 ; x < dimx ; ++x){
+        char* c = ncplane_at_yx(n_, y, x, nullptr, nullptr);
+        REQUIRE(nullptr != c);
+        if(y == dimy / 2 && x == dimx / 2){
+          CHECK(0 == strcmp(c, ""));
+        }else{
+          CHECK(0 == strcmp(c, "x"));
+        }
+        free(c);
+      }
+    }
   }
 
+  CHECK(0 == notcurses_render(nc_));
   CHECK(0 == notcurses_stop(nc_));
 
 }
diff --git a/src/tests/main.cpp b/src/tests/main.cpp
index d011fc585..693e8cf91 100644
--- a/src/tests/main.cpp
+++ b/src/tests/main.cpp
@@ -164,7 +164,9 @@ auto main(int argc, const char **argv) -> int {
   handle_opts(argv);
   int res = context.run(); // run
   reset_terminal();
-  check_data_dir();
+  if(res){
+    check_data_dir();
+  }
   if(context.shouldExit()){ // important - query flags (and --exit) rely on the user doing this
     return res;             // propagate the result of the tests
   }